Nice work. I really like the visuals and the music. Gameplay was fun as well.
Maybe it was just me, but I would prefer player 1 being controlled by WASD keys and let the arrow keys for player 2, but that's just preference, not a problem. It took me sometime to start because I immediately went for WASD keys an got no response from them.
One minor thing I would say would be good to improve is player movement. As far as I tested, it was impossible to move sideways once you are already in mid air. That was a little bit frustrating, I had to carefully go sideways and jump in order to jump to platforms. It also sometimes reacted to the input faster than I expected, making consecutive jumps when I thought it would do just one.