Cute! Has potential!
I would recommend taking a look at GMTK's Platformer Toolkit [ edit: not about Game Maker, it's just the guy's name ], which is an interactive tutorial for how tweaking different aspects of a platformer character's mechanics affects the game feel.

I would also recommend increasing the frame rate to 60.
(If you want hand-animated sections to run at a lower rate you can double or triple the keyframes, but for anything with user interaction it's best to have it running at the full 60.)

I hope you keep working on it!

Nice prototype with a fun character. Good job! I hope you will finish your platformer game because you have all the building blocks ready to go.

the prototype is cool, but I'll wait for the full game
what inspired the character design?

It's surprising this is where you chose to stop, because most of the game (collision and physics) are already there. Even the menu has some nice polish to it and the graphics are really cute. This game could still be solid even without coding in enemies or new mechanics, a simple timer and actual level design could have made this a fun game to speedrun. I look forward to seeing the final product.

I think it has potential, just adding more stuff to it and that’s it