Great idea! :D loved the concept, I'm sure your parents are proud of you :p jaja in all seriousness this concept really gets at the thee of passage in a creative manner and I love that about this!
One thing I will say, same as other people, was that that intro mouth part is pretty difficult and there is one reason that I think it might be interesting to look into. When the player character hits something it's almost impossible to come back from it, it would be nice to have some invincibility frames or if not that, a way to jump in mid-air after you've been hit (not right away of course but something to help you recover. I kept trying to pull off a recovery jump and was unable to maybe the time needed for one needs to be adjusted buy Im unsure.
Either way, fine job on this one! :D