How do you reactivate animations in scene editor?

While doing my first project, I clicked some sort of key combination that stopped the continuous animations in the scene editor. It's running fine whilst in play mode, but it's just a static image outside of that.

The cubes in the image below used to rotate in the editor, but that's no longer the case... Image:

I've tried numerous searches for this, but all I get is results regarding the Animation editor itself (naturally). I'm sorry of this is some really trivial thing, but I really can't figure it out, I believe it's just a single click somewhere, but I can't find it.

Any help would be greatly appreciated!

Edit: Added code for rotation.

 public class rotator : MonoBehaviour {
     public float speed;
     void Update () {
         transform.Rotate (new Vector3(90,60,30)*Time.deltaTime*speed);
     }
 }