The art is really really cute and I love the animations and stuff. I do think the music was a bit repetitive though. There should be a counter to track how many of the gems you've had unless memorising them was part of the design on purpose. There is no checkpoint system so that can be frustrating. The bat enemy is evil >:(
Jumping on enemies is a lot of fun due to the way they animate and the sound effects used. You could make a whole game with that artstyle and gameplay. It did feel good to move around and stuff. There definitely should be options to turn off the music and sound effects if needed. The story is cute and a bit scary but it is pretty predictable for me. I did expect a boss fight at the end tho.
I think the bat enemy sucks. The ice didn't really add much to the game. Adding checkpoints would be a great idea. A way to skip to the end of dialogue would also be helpful but that is minor. I think a more focused level design would be better and centring it around one core mechanic. The fact there is no way to get health also sucks especially if you die.
The music is alright but the art is really cute and it did feel nice to run around. In the future I'd recommend finding a central gameplay core loop as this game seems to lack that direction (I suggest jumping on enemies they are fun). It was a bit weird to see enemies that only appeared once. The way the guy with the gun is animated is adorable and I love it but he only appears a few times and it's very easy to dodge.