Simple gameplay loop in place

Assets/Scripts/CameraController.cs

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+using System.Collections;
+using System.Collections.Generic;
+using UnityEngine;
+
+public class CameraController : MonoBehaviour {
+	public GameObject background;
+	float speed;
+
+	void Awake() {
+		speed = 0.1f;
+	}
+
+	void Update() {
+		ScrollSideways ();
+	}
+
+	void ScrollSideways() {
+		//get the x & y of the mouse as a ratio
+		float mouseX = Input.mousePosition.x / Screen.width;
+		float mouseY = Input.mousePosition.y / Screen.height;
+
+		//move the camera
+		Vector3 cameraPos = transform.position;
+
+		if (mouseX < 0.20) {
+			cameraPos.x -= speed;
+		}
+		if (mouseX > 0.80) {
+			cameraPos.x += speed;
+		}
+
+		//clamp
+		float bgWidth = background.GetComponent<Renderer>().bounds.extents.x;
+		float bgHeight = background.GetComponent<Renderer>().bounds.extents.y;
+
+		transform.position = new Vector3 (
+			Mathf.Clamp (cameraPos.x, background.transform.position.x - bgWidth/2, background.transform.position.x + bgWidth/2),
+			Mathf.Clamp (cameraPos.y, background.transform.position.y - bgHeight/2, background.transform.position.y + bgHeight/2),
+			transform.position.z
+		);
+	}
+}

Assets/Scripts/CameraController.cs.meta

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Assets/Scripts/GameController.cs

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+using System.Collections;
+using System.Collections.Generic;
+using UnityEngine;
+
+public class GameController : MonoBehaviour {
+	void Update() {
+		if (Input.GetButtonDown ("Quit")) {
+			Application.Quit ();
+		}
+	}
+}

Assets/Scripts/GameController.cs.meta

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Assets/Scripts/Monster.cs

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+using System.Collections;
+using System.Collections.Generic;
+using UnityEngine;
+
+public class Monster : MonoBehaviour {
+	void OnMouseOver() {
+		if (Input.GetMouseButtonDown(0)) {
+			Destroy (gameObject);
+		}
+	}
+}

Assets/Scripts/Monster.cs.meta

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Assets/Scripts/MonsterSpawner.cs

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+using System.Collections;
+using System.Collections.Generic;
+using UnityEngine;
+
+public class MonsterSpawner : MonoBehaviour {
+	public GameObject monsterPrefab;
+	public Vector2 motion;
+	public float delay;
+
+	void Awake() {
+		StartCoroutine (SpawnMonster ());
+	}
+
+	IEnumerator SpawnMonster() {
+		while(true) {
+			yield return new WaitForSeconds (delay);
+			GameObject monster = Instantiate (monsterPrefab);
+			monster.transform.position = transform.position;
+			monster.GetComponent<Rigidbody2D> ().velocity = motion;
+		}
+	}
+}

Assets/Scripts/MonsterSpawner.cs.meta

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