This is really fun, and I also like the persistent upgrades you can get. I thought it was a little odd that you die from just one hit. I also noticed that the obstacle planes weren't relevant early in the level just because I was coasting on the bottom while eating the people (I think?). You might want to consider adding them in gradually like you did the cops or making something that forces the player to move around the screen more. I also agree that the controls intro for Shield and Fireball in the beginning was confusing when I didn't have it available to me yet. Otherwise, I really like the concept, and it's been a fun game so far!