Fun game! I managed to get all the way to stage 11.
The upgrade system is cool, and I like that you need to decide if you want to keep shooting or taking the currency.
The enemies feel really fast and unpredictable, sometimes I felt like I got hit unfairly.
The pixel art is cute, but at the late stages I had trouble distinguishing between my minions and the enemies- a good way to solve this problem is to make all the types of enemies around the same color, and all the allies a different one.
Overall I liked the game, good job.