The music is the biggest thing that sticks out to me. I'm not sure what I'd prefer but it doesn't feel quite right. The sound effects for the fish could be a little fishier too, I think. It'd be easy to ask for more control or just a little bit easier obstacles but it's a delicate balance to mess with. Maybe if you could flop a bit while mid-air? Not enough to constitute actual air-controls but just something to give the player one more bit of agency or way to add chaos into the system.
I think one of the (many) cool things about a game like Getting Over It is that some sections require a pretty specific , usually hard to accomplish, approach, but some sections are also pretty open and let you do them in at least a couple of different ways. That's going to be harder to accomplish when you only have 1 button's worth of input compared to GOI's mouse controls, but I think the way the level is designed has a big impact, irrespective of the character controls. Those first few obstacles have such a prescribed, rigid solution, so much so that they're drawn on the screen, which then takes away the fun of getting to figure out *how* to do them and only leaves the (not insignificant or unfun) challenge of *doing* them. In fairness though, I haven't finished the game as it really is very hard.
Oh, I also greatly dislike that you respawn at chip points with velocity. I would prefer to just spawn on top of the point with 0 velocity.
Really though as an idea it's perfect. And the art is all spot on too.