Added marixil's work, v1.1

Assets/Scripts/Monster.cs

@@ -13,9 +13,11 @@ public class Monster : MonoBehaviour {
 	}
 
 	Rigidbody2D rigidBody;
+	SpriteRenderer spriteRenderer;
 
 	void Awake() {
 		rigidBody = GetComponent<Rigidbody2D> ();
+		spriteRenderer = GetComponent<SpriteRenderer> ();
 	}
 
 	void OnMouseOver() {
@@ -36,6 +38,26 @@ public class Monster : MonoBehaviour {
 	IEnumerator DestroySelfAfter(float seconds) {
 		//clean up lost objects
 		yield return new WaitForSeconds (seconds);
-		Destroy (gameObject);
+		StartCoroutine (FadeCoroutine(0.01f));
+	}
+
+	IEnumerator FadeCoroutine(float period) {
+		float absolute = 1.0f;
+		float degree = -0.02f;
+
+		while(true) {
+			//wait
+			yield return new WaitForSeconds (period);
+
+			//fade routine
+			absolute += degree;
+
+			//fade
+			spriteRenderer.color = new Color (1, 1, 1, absolute);
+
+			if (absolute <= 0f) {
+				Destroy (gameObject);
+			}
+		}
 	}
 }