Let me start off by saying very well done.
The gameplay is overall smooth and satisfactory. I was actually playing this game and having fun, which sometimes people forget is the main point of all of this game making stuff (at least I know I do lol).
The art is super cute and unique, seeing that everything was done by yourself I must say I'm impressed.
Adding checkpoints could be an awesome improvement since I think now we completely reset when we die and I was pissed!
I love your art and it's one of the best highlights for me, but the bordering grey area of the map kind of seems unfitting with the rest. I really love the rest.
The game is awesome man, if you want to make it even more awesome those are some points you could look at IMO. Hats off to you though, great submission I'm sure it will do quite well ;)