Pretty good. I’d point out that the arrow keys have a bug where you cannot move diagonally, while the wasd keys work just fine. Considering how little you’re incentivised to move about, it doesn’t really matter until the later levels. I’d recommend removing the first few levels so people don’t think it’s boring; they can literally be beaten by holding down the space bar and nothing else. Some upgrade, temporary or otherwise may also give it some spice, and forcing full screen may help as it doesn’t quite fit in the window otherwise. Good job.