Playable demo game and bug fixes in sprites

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 273204c3f4f5ac513df30faee5d683a75eb555dd..0a273acb7f4be4c9367789da10354227986fbd4d 100644
--- a/sky/examples/game/main.dart
+++ b/sky/examples/game/main.dart
@@ -1,5 +1,6 @@
 import 'dart:sky';
-import 'lib/game.dart';
+import 'package:sky/framework/app.dart';
+import 'lib/game_demo.dart';
 import 'lib/sprites.dart';
 import 'package:sky/framework/app.dart';
 
@@ -11,13 +12,11 @@ void main() {
       "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",
+      "https://raw.githubusercontent.com/slembcke/GalacticGuardian.spritebuilder/GDC/Packages/SpriteBuilder%20Resources.sbpack/Sprites/resources-auto/laserBlue.png",
     ],
     allLoaded);
 }
 
 void allLoaded(ImageMap loader) {
-  // Create a new app with the sprite box that contains our game world
-  //app = new AppView(new GameBox(new GameWorld(loader)));
-  //print("hello");
-  app = new AppView((new GameTestsBox(new GameTests(loader), SpriteBoxTransformMode.nativePoints)));
+  app = new AppView(root: new GameDemoBox(new GameDemoWorld(loader)));
 }