I like the protagonist, very cute design. I echo a lot of the sentiments of other commenters though, I think it would’ve served you well to polish the core character controller some more, adding things like coyote time, jump buffers, and making the ledge grab work more consistently. When the jumps get tight, like in the final long jump gauntlet, these kind of things help a lot in terms of gamefeel.
I also think you could’ve given out the first upgrade a bit earlier, because to be honest, just jumping from platform to platform with no frills got old rather quickly. It feels a lot better late game, I had fun making big leaps over things once I got my full set. I also really liked the wall graffiti way of explaining powerups, that’s a cool way to “minimalistically” teach the player how to do stuff.
Congrats on making your first 3D game, it gets easier from here!