it looks good, but I have some feedback:
• you can walk on water • if you first move to the left and the press down without relesing the left key, and after that releas the down key you dont move left (one way to solv it would be to implement 8 directional movment, then you don't have to check for the last key, you only have to change the charachters velocity in the direction it's going) • the audio isn't looping (add the loop attribute to the audio tag)