diff --git a/src/demo/demo.cc b/src/demo/demo.cc
index 6ac88dd..ed6818b 100644
--- a/src/demo/demo.cc
+++ b/src/demo/demo.cc
@@ -13,7 +13,6 @@
 #include "engine/engine.h"
 #include "engine/game_factory.h"
 #include "engine/input_event.h"
-#include "engine/sound.h"
 
 DECLARE_GAME_BEGIN
 DECLARE_GAME(Demo)
@@ -47,16 +46,38 @@ Demo::~Demo() {
   saved_data_.Save();
 }
 
-bool Demo::Initialize() {
-  saved_data_.Load(kSaveFileName);
-
-  Engine::Get().LoadCustomShader("sky_without_nebula",
-                                 "sky_without_nebula.glsl");
-  Engine::Get().LoadCustomShader("sky", "sky.glsl");
-
+bool Demo::PreInitialize() {
   if (!font_.Load("PixelCaps!.ttf"))
     return false;
 
+  Engine::Get().SetShaderSource("sky_without_nebula",
+                                "sky_without_nebula.glsl");
+  Engine::Get().SetShaderSource("sky", "sky.glsl");
+
+  Engine::Get().AsyncLoadSound("music", "Game_2_Main.mp3");
+  Engine::Get().AsyncLoadSound("boss_music", "Game_2_Boss.mp3");
+
+  if (!enemy_.PreInitialize()) {
+    LOG << "Failed to create the enemy.";
+    return false;
+  }
+
+  if (!player_.PreInitialize()) {
+    LOG << "Failed to create the enemy.";
+    return false;
+  }
+
+  if (!menu_.PreInitialize()) {
+    LOG << "Failed to create the menu.";
+    return false;
+  }
+
+  return true;
+}
+
+bool Demo::Initialize() {
+  saved_data_.Load(kSaveFileName);
+
   if (!sky_.Create(false)) {
     LOG << "Could not create the sky.";
     return false;
@@ -87,18 +108,10 @@ bool Demo::Initialize() {
     return false;
   }
 
-  auto sound = std::make_unique<Sound>();
-  if (!sound->Load("Game_2_Main.mp3", true))
-    return false;
-
-  auto boss_sound = std::make_unique<Sound>();
-  if (!boss_sound->Load("Game_2_Boss.mp3", true))
-    return false;
-
-  music_.SetSound(std::move(sound));
+  music_.SetSound("music");
   music_.SetMaxAplitude(0.5f);
 
-  boss_music_.SetSound(std::move(boss_sound));
+  boss_music_.SetSound("boss_music");
   boss_music_.SetMaxAplitude(0.5f);
 
   if (!saved_data_.root().get("audio", Json::Value(true)).asBool())
@@ -172,6 +185,7 @@ void Demo::ContextLost() {
     num_benchmark_samples_ = 0;
     avarage_fps_ = 0;
   }
+  menu_.SetRendererType();
 }
 
 void Demo::LostFocus() {}
diff --git a/src/demo/demo.h b/src/demo/demo.h
index b3ec1ed..89ed04f 100644
--- a/src/demo/demo.h
+++ b/src/demo/demo.h
@@ -23,14 +23,12 @@ class Demo final : public eng::Game {
   Demo();
   ~Demo() final;
 
+  // Game interface
+  bool PreInitialize() final;
   bool Initialize() final;
-
   void Update(float delta_time) final;
-
   void ContextLost() final;
-
   void LostFocus() final;
-
   void GainedFocus(bool from_interstitial_ad) final;
 
   void AddScore(size_t score);
diff --git a/src/demo/enemy.cc b/src/demo/enemy.cc
index dfa2f6f..46c2144 100644
--- a/src/demo/enemy.cc
+++ b/src/demo/enemy.cc
@@ -13,7 +13,6 @@
 #include "engine/font.h"
 #include "engine/image.h"
 #include "engine/renderer/geometry.h"
-#include "engine/sound.h"
 
 #include "demo/demo.h"
 
@@ -78,46 +77,44 @@ Enemy::Enemy() = default;
 
 Enemy::~Enemy() = default;
 
+bool Enemy::PreInitialize() {
+  Engine::Get().SetImageSource("skull_tex", "enemy_anims_01_frames_ok.png",
+                               true);
+  Engine::Get().SetImageSource("bug_tex", "enemy_anims_02_frames_ok.png", true);
+  Engine::Get().SetImageSource("boss_tex1", "Boss_ok.png", true);
+  Engine::Get().SetImageSource("boss_tex2", "Boss_ok_lvl2.png", true);
+  Engine::Get().SetImageSource("boss_tex3", "Boss_ok_lvl3.png", true);
+  Engine::Get().SetImageSource("target_tex", "enemy_target_single_ok.png",
+                               true);
+  Engine::Get().SetImageSource("blast_tex", "enemy_anims_blast_ok.png", true);
+  Engine::Get().SetImageSource("shield_tex", "woom_enemy_shield.png", true);
+  Engine::Get().SetImageSource("crate_tex", "nuke_pack_OK.png", true);
+
+  for (int i = 0; i < kEnemyType_Max; ++i)
+    Engine::Get().SetImageSource(
+        "score_tex"s + std::to_string(i),
+        std::bind(&Enemy::GetScoreImage, this, (EnemyType)i), true);
+
+  Engine::Get().SetShaderSource("chromatic_aberration",
+                                "chromatic_aberration.glsl");
+
+  Engine::Get().AsyncLoadSound("boss_intro", "boss_intro.mp3");
+  Engine::Get().AsyncLoadSound("boss_explosion", "boss_explosion.mp3");
+  Engine::Get().AsyncLoadSound("explosion", "explosion.mp3");
+  Engine::Get().AsyncLoadSound("stealth", "stealth.mp3");
+  Engine::Get().AsyncLoadSound("shield", "shield.mp3");
+  Engine::Get().AsyncLoadSound("hit", "hit.mp3");
+  Engine::Get().AsyncLoadSound("powerup-spawn", "powerup-spawn.mp3");
+  Engine::Get().AsyncLoadSound("powerup-pick", "powerup-pick.mp3");
+
+  return true;
+}
+
 bool Enemy::Initialize() {
-  boss_intro_sound_ = std::make_shared<Sound>();
-  if (!boss_intro_sound_->Load("boss_intro.mp3", false))
-    return false;
-
-  boss_explosion_sound_ = std::make_shared<Sound>();
-  if (!boss_explosion_sound_->Load("boss_explosion.mp3", false))
-    return false;
-
-  explosion_sound_ = std::make_shared<Sound>();
-  if (!explosion_sound_->Load("explosion.mp3", false))
-    return false;
-
-  stealth_sound_ = std::make_shared<Sound>();
-  if (!stealth_sound_->Load("stealth.mp3", false))
-    return false;
-
-  shield_on_sound_ = std::make_shared<Sound>();
-  if (!shield_on_sound_->Load("shield.mp3", false))
-    return false;
-
-  hit_sound_ = std::make_shared<Sound>();
-  if (!hit_sound_->Load("hit.mp3", false))
-    return false;
-
-  power_up_spawn_sound_ = std::make_shared<Sound>();
-  if (!power_up_spawn_sound_->Load("powerup-spawn.mp3", false))
-    return false;
-
-  power_up_pick_sound_ = std::make_shared<Sound>();
-  if (!power_up_pick_sound_->Load("powerup-pick.mp3", false))
-    return false;
-
-  if (!CreateRenderResources())
-    return false;
-
   boss_.SetZOrder(10);
   boss_animator_.Attach(&boss_);
 
-  boss_intro_.SetSound(boss_intro_sound_);
+  boss_intro_.SetSound("boss_intro");
   boss_intro_.SetVariate(false);
   boss_intro_.SetSimulateStereo(false);
 
@@ -729,29 +726,29 @@ void Enemy::SpawnUnit(EnemyType enemy_type,
   e.movement_animator.Play(Animator::kMovement, false);
 
   if (e.enemy_type == kEnemyType_PowerUp) {
-    e.explosion.SetSound(power_up_pick_sound_);
+    e.explosion.SetSound("powerup-pick");
 
-    e.spawn.SetSound(power_up_spawn_sound_);
+    e.spawn.SetSound("powerup-spawn");
     e.spawn.SetMaxAplitude(2.0f);
     e.spawn.Play(false);
   } else {
-    e.explosion.SetSound(explosion_sound_);
+    e.explosion.SetSound("explosion");
     e.explosion.SetVariate(true);
     e.explosion.SetSimulateStereo(true);
     e.explosion.SetMaxAplitude(0.9f);
   }
 
-  e.stealth.SetSound(stealth_sound_);
+  e.stealth.SetSound("stealth");
   e.stealth.SetVariate(false);
   e.stealth.SetSimulateStereo(false);
   e.stealth.SetMaxAplitude(0.7f);
 
-  e.shield_on.SetSound(shield_on_sound_);
+  e.shield_on.SetSound("shield");
   e.shield_on.SetVariate(false);
   e.shield_on.SetSimulateStereo(false);
   e.shield_on.SetMaxAplitude(0.5f);
 
-  e.hit.SetSound(hit_sound_);
+  e.hit.SetSound("hit");
   e.hit.SetVariate(true);
   e.hit.SetSimulateStereo(false);
   e.hit.SetMaxAplitude(0.5f);
@@ -825,11 +822,11 @@ void Enemy::SpawnBoss() {
         Animator::kMovement, [&]() -> void { e.marked_for_removal = true; });
     e.score_animator.Attach(&e.score);
 
-    e.explosion.SetSound(boss_explosion_sound_);
+    e.explosion.SetSound("boss_explosion");
     e.explosion.SetVariate(false);
     e.explosion.SetSimulateStereo(false);
 
-    e.hit.SetSound(hit_sound_);
+    e.hit.SetSound("hit");
     e.hit.SetVariate(true);
     e.hit.SetSimulateStereo(false);
     e.hit.SetMaxAplitude(0.5f);
@@ -1185,30 +1182,6 @@ std::unique_ptr<Image> Enemy::GetScoreImage(EnemyType enemy_type) {
   return image;
 }
 
-bool Enemy::CreateRenderResources() {
-  Engine::Get().SetImageSource("skull_tex", "enemy_anims_01_frames_ok.png",
-                               true);
-  Engine::Get().SetImageSource("bug_tex", "enemy_anims_02_frames_ok.png", true);
-  Engine::Get().SetImageSource("boss_tex1", "Boss_ok.png", true);
-  Engine::Get().SetImageSource("boss_tex2", "Boss_ok_lvl2.png", true);
-  Engine::Get().SetImageSource("boss_tex3", "Boss_ok_lvl3.png", true);
-  Engine::Get().SetImageSource("target_tex", "enemy_target_single_ok.png",
-                               true);
-  Engine::Get().SetImageSource("blast_tex", "enemy_anims_blast_ok.png", true);
-  Engine::Get().SetImageSource("shield_tex", "woom_enemy_shield.png", true);
-  Engine::Get().SetImageSource("crate_tex", "nuke_pack_OK.png", true);
-
-  for (int i = 0; i < kEnemyType_Max; ++i)
-    Engine::Get().SetImageSource(
-        "score_tex"s + std::to_string(i),
-        std::bind(&Enemy::GetScoreImage, this, (EnemyType)i), true);
-
-  Engine::Get().LoadCustomShader("chromatic_aberration",
-                                 "chromatic_aberration.glsl");
-
-  return true;
-}
-
 void Enemy::TranslateEnemyUnit(EnemyUnit& e, const Vector2f& delta) {
   e.sprite.Translate(delta);
   e.target.Translate(delta);
diff --git a/src/demo/enemy.h b/src/demo/enemy.h
index f8d4c85..0adb1c3 100644
--- a/src/demo/enemy.h
+++ b/src/demo/enemy.h
@@ -15,7 +15,6 @@
 
 namespace eng {
 class Image;
-class Sound;
 }  // namespace eng
 
 class Enemy {
@@ -23,6 +22,7 @@ class Enemy {
   Enemy();
   ~Enemy();
 
+  bool PreInitialize();
   bool Initialize();
 
   void Update(float delta_time);
@@ -109,15 +109,6 @@ class Enemy {
   eng::Animator boss_animator_;
   eng::SoundPlayer boss_intro_;
 
-  std::shared_ptr<eng::Sound> boss_intro_sound_;
-  std::shared_ptr<eng::Sound> boss_explosion_sound_;
-  std::shared_ptr<eng::Sound> explosion_sound_;
-  std::shared_ptr<eng::Sound> stealth_sound_;
-  std::shared_ptr<eng::Sound> shield_on_sound_;
-  std::shared_ptr<eng::Sound> hit_sound_;
-  std::shared_ptr<eng::Sound> power_up_spawn_sound_;
-  std::shared_ptr<eng::Sound> power_up_pick_sound_;
-
   std::list<EnemyUnit> enemies_;
 
   int num_enemies_killed_in_current_wave_ = 0;
@@ -164,8 +155,6 @@ class Enemy {
 
   std::unique_ptr<eng::Image> GetScoreImage(EnemyType enemy_type);
 
-  bool CreateRenderResources();
-
   void TranslateEnemyUnit(EnemyUnit& e, const base::Vector2f& delta);
 };
 
diff --git a/src/demo/menu.cc b/src/demo/menu.cc
index 02efe6b..afe15c8 100644
--- a/src/demo/menu.cc
+++ b/src/demo/menu.cc
@@ -53,7 +53,7 @@ Menu::Menu() = default;
 
 Menu::~Menu() = default;
 
-bool Menu::Initialize() {
+bool Menu::PreInitialize() {
   click_sound_ = std::make_shared<Sound>();
   if (!click_sound_->Load("menu_click.mp3", false))
     return false;
@@ -70,8 +70,59 @@ bool Menu::Initialize() {
       max_text_width_ = width;
   }
 
-  if (!CreateRenderResources())
-    return false;
+  Engine::Get().SetImageSource("menu_tex",
+                               std::bind(&Menu::CreateMenuImage, this), true);
+  Engine::Get().SetImageSource("logo_tex0", "woom_logo_start_frames_01.png",
+                               true);
+  Engine::Get().SetImageSource("logo_tex1", "woom_logo_start_frames_02-03.png",
+                               true);
+  Engine::Get().SetImageSource("buttons_tex", "menu_icons.png", true);
+  Engine::Get().SetImageSource("renderer_logo", "renderer_logo.png", true);
+
+  Engine::Get().SetImageSource(
+      "version_tex",
+      []() -> std::unique_ptr<Image> {
+        const Font* font = Engine::Get().GetSystemFont();
+
+        int w, h;
+        font->CalculateBoundingBox(kVersionStr, w, h);
+
+        auto image = std::make_unique<Image>();
+        image->Create(w, font->GetLineHeight());
+        image->Clear({1, 1, 1, 0});
+
+        font->Print(0, 0, kVersionStr, image->GetBuffer(), image->GetWidth());
+
+        image->Compress();
+        return image;
+      },
+      true);
+
+  Engine::Get().SetImageSource("high_score_tex",
+                               std::bind(&Menu::CreateHighScoreImage, this));
+  Engine::Get().SetImageSource("wave_up_tex", []() -> std::unique_ptr<Image> {
+    const Font& font = static_cast<Demo*>(Engine::Get().GetGame())->GetFont();
+
+    constexpr char btn_text[] = "[  ]";
+
+    int w, h;
+    font.CalculateBoundingBox(btn_text, w, h);
+
+    auto image = std::make_unique<Image>();
+    image->Create(w, h);
+    image->Clear({1, 1, 1, 0});
+
+    font.Print(0, 0, btn_text, image->GetBuffer(), image->GetWidth());
+
+    image->Compress();
+    return image;
+  });
+
+  return true;
+}
+
+bool Menu::Initialize() {
+  Demo* game = static_cast<Demo*>(Engine::Get().GetGame());
 
   for (int i = 0; i < kOption_Max; ++i) {
     items_[i].text.Create("menu_tex", {1, 4});
@@ -199,8 +250,6 @@ bool Menu::Initialize() {
         Engine::Get().CreateRenderer(renderer_type_.enabled()
                                          ? RendererType::kVulkan
                                          : RendererType::kOpenGL);
-        renderer_type_.SetEnabled(
-            (Engine::Get().GetRendererType() == RendererType::kVulkan));
       },
       true, Engine::Get().GetRendererType() == RendererType::kVulkan,
       kColorFadeOut, {Vector4f{1, 1, 1, 1}, Vector4f{1, 1, 1, 1}});
@@ -320,6 +369,11 @@ void Menu::SetOptionEnabled(Option o, bool enable) {
   }
 }
 
+void Menu::SetRendererType() {
+  renderer_type_.SetEnabled(
+      (Engine::Get().GetRendererType() == RendererType::kVulkan));
+}
+
 void Menu::Show() {
   logo_[1].SetColor(kColorNormal);
   logo_animator_[0].SetVisible(true);
@@ -440,53 +494,6 @@ void Menu::Hide(Closure cb) {
   }
 }
 
-bool Menu::CreateRenderResources() {
-  Engine::Get().SetImageSource("menu_tex",
-                               std::bind(&Menu::CreateMenuImage, this));
-  Engine::Get().SetImageSource("logo_tex0", "woom_logo_start_frames_01.png");
-  Engine::Get().SetImageSource("logo_tex1", "woom_logo_start_frames_02-03.png");
-  Engine::Get().SetImageSource("buttons_tex", "menu_icons.png");
-  Engine::Get().SetImageSource("high_score_tex",
-                               std::bind(&Menu::CreateHighScoreImage, this));
-  Engine::Get().SetImageSource("renderer_logo", "renderer_logo.png");
-
-  Engine::Get().SetImageSource("wave_up_tex", []() -> std::unique_ptr<Image> {
-    const Font& font = static_cast<Demo*>(Engine::Get().GetGame())->GetFont();
-
-    constexpr char btn_text[] = "[  ]";
-
-    int w, h;
-    font.CalculateBoundingBox(btn_text, w, h);
-
-    auto image = std::make_unique<Image>();
-    image->Create(w, h);
-    image->Clear({1, 1, 1, 0});
-
-    font.Print(0, 0, btn_text, image->GetBuffer(), image->GetWidth());
-
-    image->Compress();
-    return image;
-  });
-
-  Engine::Get().SetImageSource("version_tex", []() -> std::unique_ptr<Image> {
-    const Font* font = Engine::Get().GetSystemFont();
-
-    int w, h;
-    font->CalculateBoundingBox(kVersionStr, w, h);
-
-    auto image = std::make_unique<Image>();
-    image->Create(w, font->GetLineHeight());
-    image->Clear({1, 1, 1, 0});
-
-    font->Print(0, 0, kVersionStr, image->GetBuffer(), image->GetWidth());
-
-    image->Compress();
-    return image;
-  });
-
-  return true;
-}
-
 std::unique_ptr<Image> Menu::CreateMenuImage() {
   const Font& font = static_cast<Demo*>(Engine::Get().GetGame())->GetFont();
 
diff --git a/src/demo/menu.h b/src/demo/menu.h
index 9a42216..5909475 100644
--- a/src/demo/menu.h
+++ b/src/demo/menu.h
@@ -30,11 +30,13 @@ class Menu {
   Menu();
   ~Menu();
 
+  bool PreInitialize();
   bool Initialize();
 
   void OnInputEvent(std::unique_ptr<eng::InputEvent> event);
 
   void SetOptionEnabled(Option o, bool enable);
+  void SetRendererType();
 
   void Show();
   void Hide(base::Closure cb = nullptr);
@@ -145,9 +147,6 @@ class Menu {
 
   Radio starting_wave_;
   Button wave_up_;
-  Button wave_down_;
-
-  bool CreateRenderResources();
 
   std::unique_ptr<eng::Image> CreateMenuImage();
   std::unique_ptr<eng::Image> CreateHighScoreImage();
diff --git a/src/demo/player.cc b/src/demo/player.cc
index a78f71e..2aeb1d2 100644
--- a/src/demo/player.cc
+++ b/src/demo/player.cc
@@ -5,7 +5,6 @@
 #include "engine/engine.h"
 #include "engine/font.h"
 #include "engine/input_event.h"
-#include "engine/sound.h"
 
 #include "demo/demo.h"
 
@@ -29,22 +28,20 @@ Player::Player() = default;
 
 Player::~Player() = default;
 
+bool Player::PreInitialize() {
+  Engine::Get().SetImageSource("weapon_tex", "enemy_anims_flare_ok.png", true);
+  Engine::Get().SetImageSource("beam_tex", "enemy_ray_ok.png", true);
+  Engine::Get().SetImageSource("nuke_symbol_tex", "nuke_frames.png", true);
+  Engine::Get().SetImageSource("health_bead", "bead.png", true);
+
+  Engine::Get().AsyncLoadSound("laser", "laser.mp3");
+  Engine::Get().AsyncLoadSound("nuke", "nuke.mp3");
+  Engine::Get().AsyncLoadSound("no_nuke", "no_nuke.mp3");
+
+  return true;
+}
+
 bool Player::Initialize() {
-  if (!CreateRenderResources())
-    return false;
-
-  laser_shot_sound_ = std::make_shared<Sound>();
-  if (!laser_shot_sound_->Load("laser.mp3", false))
-    return false;
-
-  nuke_explosion_sound_ = std::make_shared<Sound>();
-  if (!nuke_explosion_sound_->Load("nuke.mp3", false))
-    return false;
-
-  no_nuke_sound_ = std::make_shared<Sound>();
-  if (!no_nuke_sound_->Load("no_nuke.mp3", false))
-    return false;
-
   SetupWeapons();
 
   Vector2f hb_pos = Engine::Get().GetScreenSize() / Vector2f(2, -2) +
@@ -75,12 +72,12 @@ bool Player::Initialize() {
 
   nuke_symbol_animator_.Attach(&nuke_symbol_);
 
-  nuke_explosion_.SetSound(nuke_explosion_sound_);
+  nuke_explosion_.SetSound("nuke");
   nuke_explosion_.SetVariate(false);
   nuke_explosion_.SetSimulateStereo(false);
   nuke_explosion_.SetMaxAplitude(0.8f);
 
-  no_nuke_.SetSound(no_nuke_sound_);
+  no_nuke_.SetSound("no_nuke");
 
   return true;
 }
@@ -306,7 +303,7 @@ void Player::SetupWeapons() {
     beam_animator_[i].SetBlending({1, 1, 1, 0}, 0.16f);
     beam_animator_[i].Attach(&beam_[i]);
 
-    laser_shot_[i].SetSound(laser_shot_sound_);
+    laser_shot_[i].SetSound("laser");
     laser_shot_[i].SetVariate(true);
     laser_shot_[i].SetSimulateStereo(false);
     laser_shot_[i].SetMaxAplitude(0.4f);
@@ -485,12 +482,3 @@ void Player::NavigateBack() {
   Engine& engine = Engine::Get();
   static_cast<Demo*>(engine.GetGame())->EnterMenuState();
 }
-
-bool Player::CreateRenderResources() {
-  Engine::Get().SetImageSource("weapon_tex", "enemy_anims_flare_ok.png", true);
-  Engine::Get().SetImageSource("beam_tex", "enemy_ray_ok.png", true);
-  Engine::Get().SetImageSource("nuke_symbol_tex", "nuke_frames.png", true);
-  Engine::Get().SetImageSource("health_bead", "bead.png", true);
-
-  return true;
-}
diff --git a/src/demo/player.h b/src/demo/player.h
index d29a223..f920172 100644
--- a/src/demo/player.h
+++ b/src/demo/player.h
@@ -13,7 +13,6 @@
 
 namespace eng {
 class InputEvent;
-class Sound;
 }  //  namespace eng
 
 class Player {
@@ -21,6 +20,7 @@ class Player {
   Player();
   ~Player();
 
+  bool PreInitialize();
   bool Initialize();
 
   void Update(float delta_time);
@@ -41,10 +41,6 @@ class Player {
   int nuke_count() { return nuke_count_; }
 
  private:
-  std::shared_ptr<eng::Sound> nuke_explosion_sound_;
-  std::shared_ptr<eng::Sound> no_nuke_sound_;
-  std::shared_ptr<eng::Sound> laser_shot_sound_;
-
   eng::ImageQuad drag_sign_[2];
   eng::ImageQuad weapon_[2];
   eng::ImageQuad beam_[2];
@@ -101,8 +97,6 @@ class Player {
   bool ValidateDrag(int i);
 
   void NavigateBack();
-
-  bool CreateRenderResources();
 };
 
 #endif  // DEMO_PLAYER_H
diff --git a/src/demo/sky_quad.cc b/src/demo/sky_quad.cc
index 01a1424..6c2b868 100644
--- a/src/demo/sky_quad.cc
+++ b/src/demo/sky_quad.cc
@@ -21,8 +21,8 @@ SkyQuad::~SkyQuad() = default;
 bool SkyQuad::Create(bool without_nebula) {
   without_nebula_ = without_nebula;
   scale_ = Engine::Get().GetScreenSize();
-  shader_ = Engine::Get().GetCustomShader(
-      without_nebula ? "sky_without_nebula" : "sky");
+  shader_ =
+      Engine::Get().GetShader(without_nebula ? "sky_without_nebula" : "sky");
 
   color_animator_.Attach(this);
 
diff --git a/src/engine/engine.cc b/src/engine/engine.cc
index 932356c..21c01d9 100644
--- a/src/engine/engine.cc
+++ b/src/engine/engine.cc
@@ -20,6 +20,7 @@
 #include "engine/renderer/texture.h"
 #include "engine/renderer/vulkan/renderer_vulkan.h"
 #include "engine/shader_source.h"
+#include "engine/sound.h"
 #include "third_party/texture_compressor/texture_compressor.h"
 
 using namespace base;
@@ -84,6 +85,7 @@ void Engine::Run() {
 
     if (!renderer_->IsInitialzed()) {
       timer_.Reset();
+      input_queue_.clear();
       continue;
     }
 
@@ -109,7 +111,7 @@ void Engine::Initialize() {
 
   thread_pool_.Initialize();
 
-  CreateRenderer(RendererType::kVulkan);
+  CreateRendererInternal(RendererType::kVulkan);
 
   // Normalize viewport.
   if (GetScreenWidth() > GetScreenHeight()) {
@@ -134,7 +136,11 @@ void Engine::Initialize() {
 
   game_ = GameFactoryBase::CreateGame("");
   CHECK(game_) << "No game found to run.";
+  CHECK(game_->PreInitialize()) << "Failed to pre-initialize the game.";
 
+  // Create resources and let the game finalize initialization.
+  CreateRenderResources();
+  WaitForAsyncWork();
   CHECK(game_->Initialize()) << "Failed to initialize the game.";
 }
 
@@ -205,33 +211,12 @@ void Engine::RemoveAnimator(Animator* animator) {
 }
 
 void Engine::CreateRenderer(RendererType type) {
-  if ((dynamic_cast<RendererVulkan*>(renderer_.get()) &&
-       type == RendererType::kVulkan) ||
-      (dynamic_cast<RendererOpenGL*>(renderer_.get()) &&
-       type == RendererType::kOpenGL))
-    return;
-
-  if (type == RendererType::kVulkan)
-    renderer_ =
-        std::make_unique<RendererVulkan>(std::bind(&Engine::ContextLost, this));
-  else if (type == RendererType::kOpenGL)
-    renderer_ =
-        std::make_unique<RendererOpenGL>(std::bind(&Engine::ContextLost, this));
-  else
-    NOTREACHED;
-
-  bool result = renderer_->Initialize(platform_);
-  if (!result && type == RendererType::kVulkan) {
-    LOG << "Failed to initialize " << renderer_->GetDebugName() << " renderer.";
-    LOG << "Fallback to OpenGL renderer.";
-    CreateRenderer(RendererType::kOpenGL);
-    return;
-  }
-  CHECK(result) << "Failed to initialize " << renderer_->GetDebugName()
-                << " renderer.";
-
-  CreateTextureCompressors();
-  ContextLost();
+  // Create a new renderer next cycle.
+  TaskRunner::TaskRunner::GetThreadLocalTaskRunner()->PostTask(
+      HERE, std::bind(&Engine::CreateRendererInternal, this, type));
+  TaskRunner::TaskRunner::GetThreadLocalTaskRunner()->PostTask(
+      HERE, std::bind(&Engine::ContextLost, this));
+  input_queue_.clear();
 }
 
 RendererType Engine::GetRendererType() {
@@ -323,41 +308,58 @@ void Engine::ReleaseTexture(const std::string& asset_name) {
     it->second.texture->Destroy();
 }
 
-void Engine::LoadCustomShader(const std::string& asset_name,
-                              const std::string& file_name) {
+void Engine::SetShaderSource(const std::string& asset_name,
+                             const std::string& file_name) {
   if (shaders_.contains(asset_name)) {
     DLOG << "Shader already exists: " << asset_name;
     return;
   }
 
-  auto& s = shaders_[asset_name] = {std::make_unique<Shader>(renderer_.get()),
-                                    file_name};
-
-  auto source = std::make_unique<ShaderSource>();
-  if (!source->Load(file_name))
-    return;
-  s.shader->Create(std::move(source), quad_->vertex_description(),
-                   quad_->primitive(), false);
+  shaders_[asset_name] = {std::make_unique<Shader>(renderer_.get()), file_name};
 }
 
-Shader* Engine::GetCustomShader(const std::string& asset_name) {
+Shader* Engine::GetShader(const std::string& asset_name) {
   auto it = shaders_.find(asset_name);
   if (it == shaders_.end()) {
     DLOG << "Shader not found: " << asset_name;
     return nullptr;
   }
 
+  if (!it->second.shader->IsValid()) {
+    auto source = std::make_unique<ShaderSource>();
+    if (source->Load(it->second.file_name))
+      it->second.shader->Create(std::move(source), quad_->vertex_description(),
+                                quad_->primitive(), false);
+  }
+
   return it->second.shader.get();
 }
 
-void Engine::RemoveCustomShader(const std::string& asset_name) {
-  auto it = shaders_.find(asset_name);
-  if (it == shaders_.end()) {
-    DLOG << "Shader not found: " << asset_name;
+void Engine::AsyncLoadSound(const std::string& asset_name,
+                            const std::string& file_name,
+                            bool stream) {
+  if (audio_buses_.contains(asset_name)) {
+    DLOG << "AudioBus already exists: " << asset_name;
     return;
   }
 
-  shaders_.erase(it);
+  auto sound = std::make_shared<Sound>();
+  audio_buses_[asset_name] = sound;
+
+  ++async_work_count_;
+  thread_pool_.PostTaskAndReply(
+      HERE, std::bind(&Sound::Load, sound, file_name, stream),
+      [&]() -> void { --async_work_count_; });
+}
+
+std::shared_ptr<AudioBus> Engine::GetAudioBus(const std::string& asset_name) {
+  auto it = audio_buses_.find(asset_name);
+  if (it == audio_buses_.end()) {
+    DLOG << "AudioBus not found: " << asset_name;
+    return nullptr;
+  }
+
+  return it->second;
 }
 
 std::unique_ptr<InputEvent> Engine::GetNextInputEvent() {
@@ -560,6 +562,35 @@ void Engine::AddInputEvent(std::unique_ptr<InputEvent> event) {
   input_queue_.push_back(std::move(event));
 }
 
+void Engine::CreateRendererInternal(RendererType type) {
+  if ((dynamic_cast<RendererVulkan*>(renderer_.get()) &&
+       type == RendererType::kVulkan) ||
+      (dynamic_cast<RendererOpenGL*>(renderer_.get()) &&
+       type == RendererType::kOpenGL))
+    return;
+
+  if (type == RendererType::kVulkan)
+    renderer_ =
+        std::make_unique<RendererVulkan>(std::bind(&Engine::ContextLost, this));
+  else if (type == RendererType::kOpenGL)
+    renderer_ =
+        std::make_unique<RendererOpenGL>(std::bind(&Engine::ContextLost, this));
+  else
+    NOTREACHED;
+
+  bool result = renderer_->Initialize(platform_);
+  if (!result && type == RendererType::kVulkan) {
+    LOG << "Failed to initialize " << renderer_->GetDebugName() << " renderer.";
+    LOG << "Fallback to OpenGL renderer.";
+    CreateRendererInternal(RendererType::kOpenGL);
+    return;
+  }
+  CHECK(result) << "Failed to initialize " << renderer_->GetDebugName()
+                << " renderer.";
+
+  CreateTextureCompressors();
+}
+
 void Engine::CreateTextureCompressors() {
   tex_comp_alpha_.reset();
   tex_comp_opaque_.reset();
@@ -583,6 +614,15 @@ void Engine::CreateTextureCompressors() {
 }
 
 void Engine::ContextLost() {
+  CreateRenderResources();
+  WaitForAsyncWork();
+  input_queue_.clear();
+
+  if (game_)
+    game_->ContextLost();
+}
+
+void Engine::CreateRenderResources() {
   quad_->SetRenderer(renderer_.get());
   pass_through_shader_->SetRenderer(renderer_.get());
   solid_shader_->SetRenderer(renderer_.get());
@@ -620,24 +660,44 @@ void Engine::ContextLost() {
   for (auto& t : textures_) {
     t.second.texture->SetRenderer(renderer_.get());
     if (t.second.persistent || t.second.use_count > 0) {
-      auto image = t.second.create_image();
-      if (image)
-        t.second.texture->Update(std::move(image));
+      ++async_work_count_;
+      thread_pool_.PostTaskAndReplyWithResult<std::unique_ptr<Image>>(
+          HERE, t.second.create_image,
+          [&,
+           ptr = t.second.texture.get()](std::unique_ptr<Image> image) -> void {
+            --async_work_count_;
+            if (image)
+              ptr->Update(std::move(image));
+          });
     }
   }
 
   for (auto& s : shaders_) {
     s.second.shader->SetRenderer(renderer_.get());
-    auto source = std::make_unique<ShaderSource>();
-    if (source->Load(s.second.file_name))
-      s.second.shader->Create(std::move(source), quad_->vertex_description(),
-                              quad_->primitive(), false);
+    ++async_work_count_;
+    thread_pool_.PostTaskAndReplyWithResult<std::unique_ptr<ShaderSource>>(
+        HERE,
+        [file_name = s.second.file_name]() -> std::unique_ptr<ShaderSource> {
+          auto source = std::make_unique<ShaderSource>();
+          if (!source->Load(file_name))
+            return nullptr;
+          return source;
+        },
+        [&, ptr = s.second.shader.get()](
+            std::unique_ptr<ShaderSource> source) -> void {
+          --async_work_count_;
+          if (source)
+            ptr->Create(std::move(source), quad_->vertex_description(),
+                        quad_->primitive(), false);
+        });
   }
+}
 
-  if (game_)
-    game_->ContextLost();
-
-  input_queue_.clear();
+void Engine::WaitForAsyncWork() {
+  while (async_work_count_ > 0) {
+    TaskRunner::GetThreadLocalTaskRunner()->RunTasks();
+    platform_->Update();
+  }
 }
 
 void Engine::SetStatsVisible(bool visible) {
diff --git a/src/engine/engine.h b/src/engine/engine.h
index 78e1991..525a20b 100644
--- a/src/engine/engine.h
+++ b/src/engine/engine.h
@@ -19,6 +19,7 @@ class TextureCompressor;
 namespace eng {
 
 class Animator;
+class AudioBus;
 class AudioMixer;
 class Drawable;
 class Font;
@@ -73,10 +74,14 @@ class Engine : public PlatformObserver {
   Texture* AcquireTexture(const std::string& asset_name);
   void ReleaseTexture(const std::string& asset_name);
 
-  void LoadCustomShader(const std::string& asset_name,
-                        const std::string& file_name);
-  Shader* GetCustomShader(const std::string& asset_name);
-  void RemoveCustomShader(const std::string& asset_name);
+  void SetShaderSource(const std::string& asset_name,
+                       const std::string& file_name);
+  Shader* GetShader(const std::string& asset_name);
+
+  void AsyncLoadSound(const std::string& asset_name,
+                      const std::string& file_name,
+                      bool stream = false);
+  std::shared_ptr<AudioBus> GetAudioBus(const std::string& asset_name);
 
   std::unique_ptr<InputEvent> GetNextInputEvent();
 
@@ -186,9 +191,12 @@ class Engine : public PlatformObserver {
 
   std::list<Animator*> animators_;
 
-  // Managed render resources mapped by asset name.
+  // Resources mapped by asset name.
   std::unordered_map<std::string, TextureResource> textures_;
   std::unordered_map<std::string, ShaderResource> shaders_;
+  std::unordered_map<std::string, std::shared_ptr<AudioBus>> audio_buses_;
+
+  size_t async_work_count_ = 0;
 
   std::unique_ptr<ImageQuad> stats_;
 
@@ -227,10 +235,16 @@ class Engine : public PlatformObserver {
   void GainedFocus(bool from_interstitial_ad) final;
   void AddInputEvent(std::unique_ptr<InputEvent> event) final;
 
+  void CreateRendererInternal(RendererType type);
+
   void CreateTextureCompressors();
 
   void ContextLost();
 
+  void CreateRenderResources();
+
+  void WaitForAsyncWork();
+
   void SetStatsVisible(bool visible);
   std::unique_ptr<Image> PrintStats();
 
diff --git a/src/engine/game.h b/src/engine/game.h
index 54429a7..93ef9e5 100644
--- a/src/engine/game.h
+++ b/src/engine/game.h
@@ -8,6 +8,10 @@ class Game {
   Game() = default;
   virtual ~Game() = default;
 
+  // Called before async-loading assets.
+  virtual bool PreInitialize() = 0;
+
+  // Called after resources are created.
   virtual bool Initialize() = 0;
 
   virtual void Update(float delta_time) = 0;
diff --git a/src/engine/image_quad.cc b/src/engine/image_quad.cc
index c0c78af..6656da0 100644
--- a/src/engine/image_quad.cc
+++ b/src/engine/image_quad.cc
@@ -50,7 +50,7 @@ void ImageQuad::AutoScale() {
 }
 
 void ImageQuad::SetCustomShader(const std::string& asset_name) {
-  custom_shader_ = Engine::Get().GetCustomShader(asset_name);
+  custom_shader_ = Engine::Get().GetShader(asset_name);
   custom_uniforms_.clear();
 }
 
diff --git a/src/engine/platform/platform_linux.cc b/src/engine/platform/platform_linux.cc
index d911257..6d04399 100644
--- a/src/engine/platform/platform_linux.cc
+++ b/src/engine/platform/platform_linux.cc
@@ -25,6 +25,8 @@ Platform::Platform() {
   shared_data_path_ = "./";
   LOG << "Shared data path: " << shared_data_path_.c_str();
 
+  XInitThreads();
+
   bool res = CreateWindow(800, 1205);
   CHECK(res) << "Failed to create window.";
 
diff --git a/src/engine/sound_player.cc b/src/engine/sound_player.cc
index b7e16ca..06f37ae 100644
--- a/src/engine/sound_player.cc
+++ b/src/engine/sound_player.cc
@@ -17,6 +17,10 @@ SoundPlayer::~SoundPlayer() {
   Engine::Get().GetAudioMixer()->DestroyResource(resource_id_);
 }
 
+void SoundPlayer::SetSound(const std::string& asset_name) {
+  sound_ = Engine::Get().GetAudioBus(asset_name);
+}
+
 void SoundPlayer::SetSound(std::shared_ptr<AudioBus> sound) {
   sound_ = sound;
 }
diff --git a/src/engine/sound_player.h b/src/engine/sound_player.h
index 3380827..a7aa246 100644
--- a/src/engine/sound_player.h
+++ b/src/engine/sound_player.h
@@ -2,6 +2,7 @@
 #define ENGINE_AUDIO_PLAYER_H
 
 #include <memory>
+#include <string>
 
 #include "base/closure.h"
 
@@ -14,6 +15,7 @@ class SoundPlayer {
   SoundPlayer();
   ~SoundPlayer();
 
+  void SetSound(const std::string& asset_name);
   void SetSound(std::shared_ptr<AudioBus> sound);
 
   void Play(bool loop, float fade_in_duration = 0);