diff --git a/src/game/mouse/space_invaders/alien.js b/src/game/mouse/space_invaders/alien.js
index 41e2419..55f5a38 100644
--- a/src/game/mouse/space_invaders/alien.js
+++ b/src/game/mouse/space_invaders/alien.js
@@ -15,8 +15,7 @@ class Alien extends Phaser.Sprite {
 
 		Phaser.Sprite.call(this, game, this.initialX, this.initialY, 'alien_normal');
 		this.anchor.set(0.5);
-		// this.scale.set(Alien.MAX_SCALE);
-		this.setOnInitialPosition();
+		this.goWaitingRoom();
 
 
 		this.inputEnabled = true;
@@ -41,6 +40,12 @@ class Alien extends Phaser.Sprite {
 		if(!this.isActivated)
 			return;
 
+		if(!this.isOnstage) {
+			this.isOnstage = true;
+			this.goOnstage();
+			return;
+		}
+
 		if(typeof this.onFiredFunction !== "undefined")
 			this.onFiredFunction(this);
 	}
@@ -68,27 +73,35 @@ class Alien extends Phaser.Sprite {
 		this.scale.set(0);
 	}
 
-	setOnInitialPosition() {
+	goWaitingRoom() {
+		this.isOnstage = false;
+
 		this.x = this.initialX;
 		this.y = this.initialY;
-		this.scale.set(Alien.MAX_SCALE);
+		this.scale.set(Alien.WAITING_SCALE);
 	}
 
 	goOnstage() {
 		// set random position
-		let SPAWN_BOX_LEFT		= 100;
-		let SPAWN_BOX_WIDTH		= game.world.width - 200;
-		let SPAWN_BOX_TOP		= 300;
-		let SPAWN_BOX_HEIGHT	= game.world.height - 400;
+		const SPAWN_BOX_LEFT		= 50;
+		const SPAWN_BOX_WIDTH		= game.world.width - 100;
+		const SPAWN_BOX_TOP		= 250;
+		const SPAWN_BOX_HEIGHT	= game.world.height - 340;
 
 		this.x = SPAWN_BOX_LEFT + Math.random() * SPAWN_BOX_WIDTH;
 		this.y = SPAWN_BOX_TOP + Math.random() * SPAWN_BOX_HEIGHT;
 
+		// if(isDebugMode()) {
+		// 	this.game.add.graphics()
+		// 		.beginFill(0xffffff, 0.1)
+		// 		.drawRect(SPAWN_BOX_LEFT, SPAWN_BOX_TOP, SPAWN_BOX_WIDTH, SPAWN_BOX_HEIGHT);
+		// }
+
 		// start scale tween animation
 		this.shutdown();
 
 		this.tweenScaleUp = game.add.tween(this.scale)
-			.to( { x: Alien.MAX_SCALE, y: Alien.MAX_SCALE }, Alien.DEFAULT_SPEED_SEC, Phaser.Easing.Linear.None, false);
+			.to( { x: Alien.ONSTAGE_MAX_SCALE, y: Alien.ONSTAGE_MAX_SCALE }, Alien.DEFAULT_SPEED_SEC, Phaser.Easing.Linear.None, false);
 		this.tweenScaleDown = game.add.tween(this.scale)
 			.to( { x: 0, y: 0 }, Alien.DEFAULT_SPEED_SEC, Phaser.Easing.Linear.None, false);
 		this.tweenScaleUp.chain(this.tweenScaleDown);
@@ -107,4 +120,5 @@ class Alien extends Phaser.Sprite {
 }
 
 Alien.DEFAULT_SPEED_SEC		= 3000;
-Alien.MAX_SCALE				= 3;
+Alien.WAITING_SCALE			= 2;
+Alien.ONSTAGE_MAX_SCALE		= 3;
diff --git a/src/game/mouse/space_invaders/game.js b/src/game/mouse/space_invaders/game.js
index bc55688..a81b915 100644
--- a/src/game/mouse/space_invaders/game.js
+++ b/src/game/mouse/space_invaders/game.js
@@ -4,11 +4,7 @@
 class Game {
 
 	create() {
-		// this.historyRecordManager = new HistoryRecordManager();
-
 		this.game.stage.backgroundColor = '#4d4d4d';
-		// this.chartGraphics = game.add.graphics(100, game.world.height - 120);
-
 
 		// top
 		let backButton = new BackButton( () => {
@@ -18,13 +14,18 @@ class Game {
 		let fullscreenButton = new FullscreenButton(this.game);
 
 
+		// waiting room
+		this.game.add.graphics()
+			.beginFill(0xffffff, 0.1)
+			.drawRect(0, 100, game.world.width, 100);
+
+
 		// contents
-		let alien = new Alien(
-			this.game.world.width / 2, this.game.world.height / 2,
-			this.onAlienFired, this.onAlienEscaped
-		);
+		let alien = new Alien(100, 150, this.onAlienFired, this.onAlienEscaped);
+		alien.goWaitingRoom();
+
+		// activate first alien
 		alien.setActive(true);
-		alien.goOnstage();
 
 
 		// bottom
@@ -81,7 +82,6 @@ class Game {
 
 	onAlienEscaped(sprite) {
 		console.log("onAlienEscaped");
-		// sprite.goOnstage();
 	}
 
 }
\ No newline at end of file