Your mission in this shooting game is to resist for 30 minutes to the stronger and stronger waves of aliens attacking your base. Kill all of them using at best all your weaponry with the D-orgone beamer cannon included. Upgrade your base and weapons to survive even the attacks of strongest aliens. Use YOUR MOUSE to aim and shoot. Hold "A" KEY to shoot with left cannon only, hold "B" KEY to shoot with right cannon only. Use "Q" and "Z" KEYS to switch left cannon weapon, use "E" and "C" KEYS to switch right cannon weapon. Press 1-5 NUMBER KEYS for special attacks. Press the SPACEBAR to manage upgrades. Good luck!