Arrow keys to move. Z to kick. X to throw a projectile. S to skip intro slideshow as well as duck. R to restart. In order to get the lowest score (and thus, the highest rank), you must defeat the gel in a timely fashion as well as maintaining a high amount of health. The stats that you choose at the beginning also play a role in getting the lowest score. The lower the stats, the lower the score.
Credits @griffpatch for general collision detection A sonic inspired racing game on Scratch for the rank system (if anyone can find it, please link it to me). To-do List