Loved the high amount of different upgrades :D! Very fun game :)!
Some points:
- restricting yourself from an upgrade for 33% of health feels very punishing
- slimes get bugged in corners way too often
- lacking feedback that you do/don't have a bullet
- "one bullet" isn't very original
Don't think of me bad, I really liked your game :D (one of the best so far)! Just giving some negative feedback, too.