Super Mario Boards

Maybe one of the Koopalings (not to torture them lol; I actually like the Koopalings)?

I don't think bosses work, unfortunately. I can stack all 7 I am limited to on their 2x2 space and they all jump out and space themselves out

Oh, okay. What about other enemies like goombas and powerups like fire flowers?

Most act similarly to what they usually do, but multiple stacked on one space. You can overlap a Hard Block and Brick Block and destroy the Hard Block with a Mushroom-powered jump. Unchained Chomps all spread out and give a massive BARK when they spawn. Arrows freak out, and Tracks act like tracks that have an end undone that drop oonto the first Track you placed. I need to keep experimenting with other enemies, but it is certainly funny to break my favorite games occasionally.