Done some Stuff, and some more ...

Assets/Scripts/Entities/Collectable.cs

@@ -4,5 +4,5 @@ using UnityEngine;
 
 public class Collectable : Entity{
 
-	public Collectable (EntityObjective referringObjective, GameObject entityPrefab) : base(referringObjective, entityPrefab) {}
+	public Collectable (EntityObjective referringObjective) : base(referringObjective) {}
 }

Assets/Scripts/Entities/Entity.cs

@@ -2,31 +2,19 @@
 using System.Collections.Generic;
 using UnityEngine;
 
-public abstract class Entity {
+public abstract class Entity : MonoBehaviour{
 	EntityObjective referringObjective;
-	GameObject entityPrefab;
-	GameObject instance;
 
 	// Constructor
-	public Entity(EntityObjective referringObjective, GameObject entityPrefab)
+	public Entity(EntityObjective referringObjective)
 	{
 		this.referringObjective = referringObjective;
-		this.entityPrefab = entityPrefab;
-	}
-
-	// spawns the entity
-	public void Spawn(Transform spawnPoint)
-	{
-		// instance = GameObject.Instantiate (entityPrefab);
-		// instance.transform = spawnPoint;
 	}
 
 	// kills the entity
 	public void Kill()
 	{
-		GameObject.Destroy (instance);
-		referringObjective.Remove (this);
-
-		instance = null;
+		if(referringObjective != null)
+			referringObjective.Remove (this.gameObject);
 	}
 }

Assets/Scripts/Entities/Mob.cs

@@ -2,15 +2,35 @@
 using System.Collections.Generic;
 using UnityEngine;
 
-public class Mob : MonoBehaviour {
+public abstract class Mob : Entity {
+	readonly int maxHP;
+	int currentHP;
+	bool isDead;
 
-	// Use this for initialization
-	void Start () {
+	// Constructor
+	public Mob(EntityObjective referringObjective, int maxHP) : base(referringObjective)
+	{
+		this.maxHP = maxHP;
+		currentHP = maxHP;
 
+		isDead = false;
 	}
 
-	// Update is called once per frame
-	void Update () {
+	// inflicts damage to this mob
+	public void InflictDamage(int damage)
+	{
+		currentHP -= damage;
+		if (!isDead && currentHP <= 0) 
+		{
+			base.Kill ();
+			isDead = true;
+		}
+	}
 
+	// Heals the mob
+	public void Heal(int healAmount)
+	{
+		if (!isDead)
+			currentHP = (currentHP + healAmount > currentHP) ? maxHP : currentHP + healAmount;
 	}
 }

Assets/Scripts/Objectives/EntityObjective.cs

@@ -3,13 +3,14 @@ using System.Collections.Generic;
 using UnityEngine;
 
 public class EntityObjective : Objective{
-	List<Entity> entityList;
+	List<GameObject> prefabList;
+	List<GameObject> entityList;
 	List<Transform> spawnPointList;
 
 	// Constructor
-	public EntityObjective(Room objectiveCaller, List<Entity> entityList) : base(objectiveCaller)
+	public EntityObjective(Room objectiveCaller, List<GameObject> prefabList) : base(objectiveCaller)
 	{
-		this.entityList = entityList;
+		this.prefabList = prefabList;
 		spawnPointList = objectiveCaller.GetSpawnpoints ();
 	}
 
@@ -18,14 +19,17 @@ public class EntityObjective : Objective{
 	{
 		Random newRand = new Random ();
 
-		foreach (Entity i in entityList)
-			i.Spawn(spawnPointList[Random.Range(0, spawnPointList.Count)]);
+		foreach (GameObject i in prefabList) 
+		{
+			GameObject tempObject = GameObject.Instantiate (i);
+			tempObject.transform.position = spawnPointList [Random.Range (0, spawnPointList.Count)].position;
+		}
 
 		objectiveCaller.Lock();
 	}
 
 	// Removes the entity from the list and completes the objective, if the list is empty
-	public void Remove(Entity inputEntity)
+	public void Remove(GameObject inputEntity)
 	{
 		entityList.Remove (inputEntity);
 		if (entityList.Count == 0)