I played your game on Linux using Wine, which is a non-native experience that might have issues through no fault of your own.
Enjoyment
After the tutorial I couldn't kill the first enemy because they would fly into the air in a spazzy fashion and then come down on my head and sit on me. I couldn't shoot up so I would die.
Creativity
The weapons are where this game shines for sure. I thought the unique effects and applications of those effects was a really creative way to explore the theme. Good job!
Presentation
I don't particularly like the art and I especially disliked the handwritten instructions on the tutorial. It would have looked more professional to use a real font.