diff --git a/resources/image/background/star_7x7.png b/resources/image/background/star_7x7.png
new file mode 100755
index 0000000..2c5c51d
Binary files /dev/null and b/resources/image/background/star_7x7.png differ
diff --git a/resources/image/character/alien/green_alien.afdesign b/resources/image/character/alien/green_alien.afdesign
new file mode 100644
index 0000000..008aa8e
Binary files /dev/null and b/resources/image/character/alien/green_alien.afdesign differ
diff --git a/resources/image/character/alien/green_alien.png b/resources/image/character/alien/green_alien.png
new file mode 100644
index 0000000..8315e4f
Binary files /dev/null and b/resources/image/character/alien/green_alien.png differ
diff --git a/src/game/global/global_variables.js b/src/game/global/global_variables.js
index c92d1ac..b749ede 100644
--- a/src/game/global/global_variables.js
+++ b/src/game/global/global_variables.js
@@ -3,7 +3,7 @@ const LANGUAGE_ENGLISH		= "english";
 
 const MODE_RELEASE			= "release";
 const MODE_DEBUG			= "debug";
-const runMode = MODE_DEBUG;
+const runMode = MODE_RELEASE;
 
 function isDebugMode() {
 	// console.log("debug mode ? " + runMode);
diff --git a/src/game/mouse/space_invaders/game.js b/src/game/mouse/space_invaders/game.js
index 244ddd6..ffcd8fe 100644
--- a/src/game/mouse/space_invaders/game.js
+++ b/src/game/mouse/space_invaders/game.js
@@ -35,6 +35,16 @@ class Game {
 		heartGauge.start();
 
 
+		// game stage
+		let stars = game.add.group();
+
+		for (let i = 0; i < 128; i++)
+		{
+			let randomY = game.rnd.integerInRange(60, GAME_SCREEN_SIZE.y - 80);
+			stars.create(game.world.randomX, randomY, 'star');
+		}
+
+
 		// waiting room
 		this.game.add.graphics()
 			.beginFill(0xffffff, 0.1)
diff --git a/src/game/mouse/space_invaders/loading.js b/src/game/mouse/space_invaders/loading.js
index 4ba8b55..d107424 100644
--- a/src/game/mouse/space_invaders/loading.js
+++ b/src/game/mouse/space_invaders/loading.js
@@ -34,7 +34,11 @@ class Loading {
 
 	startLoading() {
 		this.game.load.image('icon_fullscreen',	'../../../resources/image/icon/fullscreen_white.png');
-		this.game.load.image('alien_normal',	'../../../resources/image/character/alien_normal.png');
+
+		this.game.load.image('star',	'../../../resources/image/background/star_7x7.png');
+
+		this.game.load.image('alien_normal',	'../../../resources/image/character/alien/green_alien.png');
+
 		this.game.load.image('heart_full',		'../../../resources/image/ui/heart_full.png');
 		this.game.load.image('heart_empty',		'../../../resources/image/ui/heart_empty.png');
 		// this.game.load.image('a', '../../../resources/image/icon/fullscreen_white.png');