Funny game. I was able to recognize well where I was... I had no problem at all with controls and to complete the game.

For players who go into the wrong pipe at the beginning, you could add a strong push upward (nobody likes a cornelius in the lungs ahah)

nice !

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

Love the art-style!

This was an interesting little game to play through! Nicely done.

I did get a little miffed at the slippy friction of your character. It makes sense in other levels, because insides be slippery, but not in the mouth level as much. Those physics made me spend an embarrassing amount of time trying to get inside...

Other than that, I really like this game. I'd love to see it in a store somewhere as a full game someday.