A sequel to Worms 2, Worms Armageddon expands upon its predecessor by enhancing a few facets of gameplay and including play over the Internet through Team17's WormNET service. Multiple new weapons have been added, as well as new singleplayer missions, challenges, and sound banks.
Like the previous Worms installments, the game is an artillery variant. The player give an artillery piece a shot angle and shot power, and try to hit the opponent, taking into account wind effects. The player and the opponent exchange these shots in a turn-based fashion. The game puts the player in command of a team of up to eight worms, which can move around the landscape (one at a time), using many types of weapons to try to dispatch the enemy, from bazookas to mini-guns to exploding sheep. In some situations, the worms can also jump, swing by rope, and descend with a parachute.
The game includes an expansive editor that allows players to customize nearly every aspect of the game. Custom teams can be created, and players are able to edit their special weapons, grave markers, flags, victory fanfares, and voice sets, which can be imported into the game from outer sources. A random terrain generator and a terrain-import system are provided as well. The latter makes it possible to import into the game files in image formats, which the game converts into playable terrains.