I really love this game! Switching between the different play styles is a really cool idea and worked really well. It also helps keep the game feeling fresh and makes me want to continue playing. Switching color palettes between play styles is a great idea too and I think this is one of the only games I've seen to take advantage of that part of the jam rules.
Just a few nitpicks.
1. In platformer mode it was difficult to land in the right place because of how the player falls quickly.
2. In topdown shooter mode, I would suggest allowing the player to hold down the mouse button for continuous fire. My finger got pretty tired from clicking after playing for a while. Also maybe the enemy bullets could've been a little slower - felt kind of random whether or not I was able to dodge them.
Really awesome entry. Definitely one of my favorites from the jam.