[W, A, S, D] ---> Move upwards, left, downwards and right, on the same order the keys are shown here.
[ENTER] ---> Shoot a basic bullet;
[SHIFT] + [ENTER] ---> Spawn Sigma, a character that shoots bullets automatically and helps you to defeat the functions;
[SHIFT] + ---> Switch to Pi mode;
[SHIFT] + [E] ---> Switch to Euler mode;
[CLICK]: {E=MC² Button} ---> Respawn after dying