This was really fun to play! I love all the cool combinations, but my favorite is the medusoform with the shotgun like attack. A suggestion I have is to give more player feedback. For example, I noticed a lack of particle systems. You could put one where a bullets collides with an enemy or when an enemy dies or even when you collect resources. Also I think it would be better if the screenshake when shooting was a little less jarring. But other than that, I thought the idea was really cool, and the music really had me bopping.