What a fun game to play. I really enjoyed it and the modes are really unexpected.
Some feedback I would like to list down:
1) Having a score system or a stage counter would be great for the player to feel like he is progressing.
2) Display the modes maybe at the top of the screen so that players that couldn't catch it at first can still read it.
3) Not sure if this is intended or a bug, but I wont die even after the enemy touched me. Which somehow makes the shooting kinda useless as I can just ramp through them