Adds (somewhat crappy) controls to example game

sky/examples/game/main.dart

Index: sky/examples/game/main.dart
diff --git a/sky/examples/game/main.dart b/sky/examples/game/main.dart
index 9d54b06a0a0f63bd2071e7fdc27336d880dc86bb..e3a76b341fec4ac0bed3c07a7ab9f1b1b422b1fa 100644
--- a/sky/examples/game/main.dart
+++ b/sky/examples/game/main.dart
@@ -10,11 +10,12 @@ void main() {
   new ImageMap([
       "https://raw.githubusercontent.com/slembcke/GalacticGuardian.spritebuilder/GDC/Packages/SpriteBuilder%20Resources.sbpack/resources-auto/BurnTexture.png",
       "https://raw.githubusercontent.com/slembcke/GalacticGuardian.spritebuilder/GDC/Packages/SpriteBuilder%20Resources.sbpack/Sprites/resources-auto/asteroid_big_002.png",
+      "https://raw.githubusercontent.com/slembcke/GalacticGuardian.spritebuilder/GDC/Packages/SpriteBuilder%20Resources.sbpack/Sprites/resources-auto/GG_blueship_Lv3.png",
     ],
     allLoaded);
 }
 
 void allLoaded(ImageMap loader) {
   // Create a new app with the sprite box that contains our game world
-  app = new AppView(new SpriteBox(new GameWorld(loader),SpriteBoxTransformMode.letterbox));
+  app = new AppView(new GameBox(new GameWorld(loader)));
 }