The arrow controls
Ghe arrow controls were awkward since they're from Cuboy's perspective. I'd press Up and wonder why he's going left, it slowed down gameplay as I had to think about which key I had to press to correspond with Cuboy's perspective. If you could change it so that the direction of each arrow doesn't change with Cuboy's perspective, like just do it the way most games do, I think it'd improve the gameplay.
I do understand that it's just a holdover game until a more serious project is released, but I hope you keep my comment in mind for those bigger projects.