This is possibly the best game I've played so far in LD49! Played on a controller, and the controls are silky smooth. Love the cute art style, and the design of the gameplay is really well thought out! It is quite a hard game, though, and I couldn't complete all the levels :(
Here comes some suggestions:
The levels are, (in my opinion :p), not arranged in order of difficulty. This is not necessary of course, but if you would make this a full game later on, and choose to lock certain levels until others have been completed first, then maybe it is good to increase difficulty gradually.
Maybe add a charge-up attack? Not necessary in any way, but could be fun!
Jump height could be higher, or maybe a double-jump ability could be added.
Also a small nitpick, I noticed that some fonts didn't reeeeally match the game's aesthetic. Could just be personal opinion, though!
Really well polished and could very well be a must-play from this year's Jam, especially if you have a controller! Fits the theme very well too!
Awesome work!
EDIT: Forgot to mention that the sound design is awesome and super cute!