W, A, S, D to move. Press space to shoot. You get 5 lives if your hit 5 times you die. There are waves and it progressively gets harder. Press 1 for pistol, 2 form machine gun, 3 for shotgun, and 4 for sniper (Must purchase 2, 3, and 4). Press P to open the shop and close it. Use the shop to upgrade the pistol, purchase the machine gun, purchase the shotgun, purchase the sniper, and upgrade damage.
I used Warframe's scratch tutorial to help but improvised a "bit".
