Nice one Scrumbo! Very fun mechanic, and good variation with the bonus slime and the mutagen stage. Felt like I could probably keep playing and getting skilled at it which is nice and makes it very replayable. I'm not really sure what you were going for with the MC changing I think from like a heart to a brain or something? But it all fit the theme of the immune system well. I would like to see you experiment with adding some more juice to the lazer and bullets and enemies (like enemies tweening in, bullets having a death animation, lazer tweening in) instead of it all just appearing/disappearing, but it's a game jam after all! Nice work man