It took a few tries to get used to the controls. Hiding with the space bar and unhiding with W kept bothering me. I'd have liked the keys to be closer together.
With a few more mechanics / other enemies, I'm sure you can get a few more levels out of it to flesh out the narrative a bit more. I liked that the colours became more intense towards the end.
It's quite a short experience, but that's not a bad thing. In the last level you had to wait a lot, and that can get boring very quickly. Especially if you get greedy against your better judgement. :)