WASD to move in a way. For W moves you forward, just like in an fps game. S is to move backward and both A and D for to the sides. Mouse to aim, click to shoot. Z to buy doors, debris, weapons, etc.
Shoutout to coolgames_idk for the zombie collision and for recommending the zombie AI for this game. There'll be more updates in the near future so if there are any bugs or glitches, let me know.