This is really snazzy! The music is really catchy, and I just love the retro Gameboy esthetic. Very cool.
The goals could be a bit clearer. The level exits don't necessarily look like exits, and the collection of coins doesn't thematically translate to opening doors. Also, I was slightly surprised when the bananas hurt me--food in videogames is usually good for healing, and this goes doubly because of the association between monkeys and bananas. I did, however, finish the game through trial and error, so it all made sense eventually.