I think I saw you post an image of the game in the progress updates on discord! Glad I stumbled onto it, the faces are just awesome.
I love the idea and the level design really delivers. Keeping the controls of each character simple makes the management of swapping between so many somewhat reasonable. The levels really made sure I used them all too (though I wish that last level told me to swap to the big guy before I dropped onto all the enemies!)
I think some sections I could skip if I wanted to since we could stick to walls to get infinite jumps. I'd also have loved some extra sfx eg for squishing the enemies, and maybe some UI to remind me which character was paired with each number.