Figured out you can cheese the platform levels by falling off so that you're infinitely falling, then move just to the side of a platform. The box's collider will stick out over the edge and you can kill them without fear of dying.
I think the application of the theme is a little loose but the game itself is fun and feels pretty mechanically polished for a game jam game. Movement felt good and level design felt fun and interesting. Had to think about a few of them.
Only real complaint was the box falling in the "background" was very distracting and I thought it was in the foreground for a long time and was trying to avoid it while platforming lol