Fun game. I think the enemy hitbox is slightly too large as it can feel unfair sometimes when you get hit, also the levels with the cloudy backgrounds cause a bit of lag on my pc, I'm assuming you used the GameMaker effect layer for that? It is known to cause some frame rate issues if you overdo it, but it wasn't anything gamebreaking! The art is especially good and I love all the different animations for walking, running and sliding. Some of the levels took a few attempts to complete, but I didn't find it unfairly difficult. Good job!