Add GameState to keep track of state and wave #

Assets/GameState.cs

@@ -0,0 +1,36 @@
+using UnityEngine;
+
+public class GameState : MonoBehaviour
+{
+	public string state;
+	public uint wave = 1;
+	public GameObject ratbot;
+
+	void Start() {
+		NewWave();
+	}
+
+    // Update is called once per frame
+    void Update()
+    {
+        if (GameObject.FindGameObjectsWithTag("Ratbot").Length == 0 && state == "WAVE") {
+			OpenShop();
+		}
+    }
+	void OpenShop() {
+		state = "SHOP";
+		NewWave();
+	}
+	void CloseShop() {
+		
+	}
+	public void NewWave() {
+		state = "WAVE";
+		Vector3 position = GameObject.FindGameObjectWithTag("Player").transform.position;
+		for (uint _ = 0; _ < wave; _++) {
+			GameObject newRatbot = Instantiate(ratbot);
+			newRatbot.GetComponent<Ratbot>().damageStrength = 5+wave*5;
+		}
+		wave++;
+	}
+}