Well, one bug was that you could win while you were dead. So if you died but also reached the finish line before you spawn, you can move on to the next level. You could also use your grapple hook while dead too. There was also a spot in level 11 towards the goal where you could go out of bounds and get respawned even though it did not look like it was out of bounds. Not sure how to explain it, but you know the tiny rocks that you can grapple and hook around in a circular motion? There was one of those rocks on the top side of the stage close to the green portal that if you hooked on to it and went to the portal, you would go out of bounds.
Overall the game is great and I can't think of something to change. Only to keep working on it and add more levels/enemies to the game.
You guys made a great game and should be proud of it!