You're surrounded by ennemies and you have to survive as much as you can, but it's not easy! You can play in 1 of these 2 modes: ESCAPE MODE: you're surrounded by enemies and you have a single bullet: dodge them as much as you can, because you lose when they reach you. SURVIVAL MODE: use your weapons as fast as you can, switch them when you run out of ammunitions and survive as long as you can against endless waves of enemies.
Use the W-A-S-D keys to move and jump (or space bar to jump). Aim and shoot with the mouse. In the survival mode: Q key to switch weapons; and E key to pick up and release objects.