Added a bunch of stuff

Assets/Scripts/Monster.cs

@@ -3,9 +3,22 @@ using System.Collections.Generic;
 using UnityEngine;
 
 public class Monster : MonoBehaviour {
+	public int value;
+
+	void Awake() {
+		StartCoroutine (DestroySelfAfter (30f));
+	}
+
 	void OnMouseOver() {
 		if (Input.GetMouseButtonDown(0)) {
+			//TODO: play death sound
+			PersistentData.score += value;
 			Destroy (gameObject);
 		}
 	}
+
+	IEnumerator DestroySelfAfter(float seconds) {
+		yield return new WaitForSeconds (seconds);
+		Destroy (gameObject);
+	}
 }