Beat all levels. I like the idea, but too much of the challenge comes from imprecise movement (too fast accel/decel/topspeed) and the fact that the game doesn't hold "down" for you at all times. If the basic controls are too difficult then higher level gameplay cannot emerge. Instead of using spacebar and mouse for jump and parry, map them to keys which the player can access with their opposite hand (whether they use WASD or arrows to move).