The game is aesthetically pleasing but I couldn't keep playing after the third level. All it did thus far was spam ten enemies around me every time I walked through X spot or picked up Y thing. It didn't feel challenging, it didn't feel like I was making intelligent use of the space. I just kept spamming the gun until I got through while hearing the same death noises ten times per second.
If that's what you're going for, then I guess it's just not for me. You should however probably make it clearer when enemies are going to deal damage, visually.