I beat it! Very cool implementation of the theme. I appreciated that to start the game you have to learn how to control the characters first. Controlling the characters themselves took awhile to get used to, but I think I got the hang of it (mostly). The music was poppy and cheerful and the SFX were a good queue to what to do next (finishing a level was particularly satisfying).
Something I was unsure of was why at least one of the buttons didn't work, it made a "clunk" sound. Is it just a red herring button or was I doing something wrong (I was able to use the other button in the level to open the door, so I'm guessing it was just a red herring).
I never really understood the purpose of the rats (I think?). When I first encountered them I just stayed big to keep them from hurting me, but later I found out they don't even hurt me when I'm small, and they didn't really prevent me from moving in my desired direction either. I'm kinda thinking it was something where you discovered being chased while controlling two characters was just too difficult to wrap your mind around, but I dunno, I'm curious!
Anyway, very cool, very good use of the theme, and it was satisfying as heck to beat the game. Good job!