From the graphics to the gameplay, this game was really nice and challenging for me. I saw in the comments you used Unitys shaders to create the graphics used here which was a really nice touch to the concept of you game.
The only thing maybe I can address was the shooting was somewhat hard for me slightly as I was moving and shooting. The shots weren't aligned with the mouse for some reason, but maybe that could be me.
Overall though, awesome job on this game!