Ok, I enjoyed this very much. So much so that I lost track of the hour I was playing it. But it also has its issues. Lets get those out of the way first. First the collisions needs some work at first I thought I might just be missing, which still might be the case for some, but it is most apparent in the boss fight. There are bullets constantly not being detected even though they go through its body. Second, once I discovered the boss room I didn't feel like I needed to explore anymore, part of it is because of the heat mechanic cause the more time I fight other enemies the more I get burnt. Third, I felt that the shooting weapon was the only viable option since moving it to attack the shooting enemies was to risky since their shooting does not get interrupted.
Now for the good stuff. The art is amazing and the sound effects are on point! The player movement and animations are super fluid. It is fun to control and to try out different weapons. The enemy have good verity and can easily overwhelm you if you're not careful. Great work on this game and I hope you update it in the future!