Very cute game!! I managed to get a star on all levels (Bass Sides-4 was personally the toughest one to clear). Some levels can be completed in fewer swaps than the star requirement, and that allows for some creative solutions, which is nice – but at the same time I think that the tougher levels shouldn’t be as lenient (I only used 4 swaps for Bass sides-3, while the star requirement was 8).
Adding an undo button would make the game feel smoother, but I’m not sure how it would have to work for airborne states. Maybe just resetting to the last grounded position before the last swap action would work?
Anyways, the level design is superb, and I would gladly play more if you ever decided to update the game :-) Oh and I also have to mention it somewhere – the soundtrack’s absolutely amazing, good job on that too ^^