Operation Carnage is an arena shooting game similar to Smash TV. The player controls a guy who tries to wreak havoc on the evil aliens who conquered and subdued Earth with soft takeover tactics. The humans are now bred like cattle and the Aliens feed off their souls.
There are 8 sectors and each sector is divided into rooms. In each room the player needs to mow down all enemies, after which a door will open to the next room. There are power-ups and weapons to be picked up, such as a machine gun, fire gun, plasma gun, scatter bomb, energy, bonus points etc. In the last room of each sector the player faces an end boss in the form of a big space ship or alien.