Killzone 2 is the third game in the Killzone franchise and continues the story two years after the events of the first two games. The game takes place on Helghan, the home-world of the Helghast who assaulted the Interplanetary Strategic Alliance's colony on Vekta. The ISA retaliates on the Helghan's own ground with the aim to secure the Helghast leader, Emperor Visari, and bring the Helghast war machine to a halt. Assuming the role of Sergeant Tomas "Sev" Sevchenko, a battle-hardened veteran and a member of the special forces unit known as the Legion. Under his command, players lead a group of highly trained soldiers on a mission to take out the Helghast threat.
The gameplay consists of scripted, cinematic gameplay, focusing on taking cover and peeking from behind objects to open fire. The game is played entirely from the first-person perspective, except for portions with vehicular combat using a tank and an exoskeleton. In addition to the single-player campaign, there is squad-based multiplayer called Warzone with various mission types, including Assassination, Search & Retrieve, Search & Destroy, Bodycount, and Capture & Hold. This mode supports up to 32 players, including bots that fill remaining spots.