Not a bad little platformer but as others have suggested, WASD would probably be a better control scheme. Spacebar for jump would also be preferable to most. You could just make the controls configurable or have multiple control schemes selectable in the options menu. I was able to work around this of course because all of my keys are configurable but it could be pretty awkward for others. I'd also recommend working with someone to create a bit of music for the stages. It's a bit bland and silent but not a bad little game.
Good luck with future projects!