Pretty neat idea, and absolutely lovely visuals, though I will say the death system is pretty unforgiving. Messing up one jump and having to go all the way back to the start is kinda demotivating after a bit, especially when it's sometimes required to jump on balloons directly over spikes. Checkpoints or just resetting to the start of the room would be nice! It would also be nice to have a little more influence on the horizontal speed of the balloons, as the bits that require pushing them can sometimes involve just standing there watching them slowly float. The mechanics are really solid though, I'd love to see this expanded, especially if it's in the direction of a Metroidvania-type game with different balloons as upgrades.