The story of Doom II takes place on Earth after the demonic invasion. The protagonist, a space marine, must find a way to bring down the force field around the last operational star port to allow humanity's escape. With the demons having killed or possessed most of the inhabitants, it's a daunting task for the hero.
The gameplay is similar to its predecessor, with 3D graphics and 2D sprites for enemies. The player navigates through 3D environments from first-person view, shooting demons while searching for switches, keys, and exits. Unlike Doom , which had three episodes, Doom II has one long episode consisting of 30 levels plus two secret levels.
The game introduces a new weapon, the super shotgun, as well as more advanced demon types with unique attacks, such as the Heavy Weapon Dudes, Revenants who launch homing missiles, and the Arch-Viles with a highly damaging fire attack.