Hi ! Cozy little game in appearance you made there ^^ I'm not the best Platformer player of all time (I'm really bad) but I think it's also due to the stiffness of the controller you made. (I did the 1rst and 2nd levels)
Getting the character movement to feel right is one of the trickiest part but also the most interesting part of making a platformer game. We’ll keep working on it and try to improve it in the next update.
Thank you for your time :)