Quake II (1997)

Quake II is a single-player and multiplayer first-person shooter. The story follows a futuristic war between Earth and the Strogg, a cybernetic alien race that invades other worlds and assimilates their inhabitants. Earth launches Operation Alien Overlord, a massive strike on the Strogg homeworld. The player assumes the role of Bitterman, a marine dropped into the invasion force. After his landing craft is destroyed, he must fight alone through enemy territory, sabotage Strogg defenses, and push toward their capital city with the ultimate goal of eliminating their ruler, the Makron.

Gameplay progresses through interconnected levels that form larger units called "hubs". Objectives include disabling security systems, destroying key facilities, and locating power sources that allow access to the next area. Unlike strictly linear shooters, progress in one map may unlock new paths or change conditions in another, creating a sense of continuity across missions. Objectives are tracked on-screen to guide players through the campaign.