Mechanic is interesting and puzzles are clever. However, level design and/or the single input makes this feel hard where maybe it shouldn't? The fact that you can't just stop moving, makes the platforming very demanding, especially for a puzzle game. This could be fixed either by making bigger platforms, that don't require precise jumps and stomps, rethinking the controls (move on hold, stop on release, jump on double tap, stomp on triple tap?), or abandoning the One Button Jam requirement.
Or I am just bad at 2D platforming, which happens to be true :D