Wow, great game! And so much content for a game jam. I finished it, and I can say it wasn’t… a piece of cake. B)
… Nevermind. So as I said, a lot of levels, enemies & characters (with various moves), and each with their own sprites. The musics were nice, and cool sounds effects (though I would have decreased the volume of some, such as crushing cans). You even added a boss fight, with awesome animations! The patterns were a little hard to read sometimes, and it seemed to glitch a little? (At one point it was “jumping” up and down around the room, but it would teleport to the top position instead.) But I had enough butter stacked to brute-force it.
They were some animations not playing correctly, and fighting some enemies was not always smoothly (hit boxes? enemies going to fast? too much delay in the attacks?… hard to say), but nothing really bad.
I didn’t understand until the very end how to use the “vents”. Retried the game again with the cheats, and tried every character until I got it: it was the ghost!
Anyway, good job!