What do you mean computer art? I placed each pixel manually from the prototype and concept art while planning the idea when the gamejam began, to the very final touches and all aspects of the game. I was even recording a small footage of prototype art because I'm planning to make a youtube video, but I'm too lazy to finish it, or even start making it in the first place lol. 
Sounds & graphics are very pleasant to me, also the checkpoint system is very well. Its a classical game but also innovative by redesign things we could have seen in a Wario game. Also the progression persistance in the browser is a very good idea!
Just a ting for a future update: mapping the Q key to LEFT would make the game AZERTY compliant