Killzone is a squad-based, first-person shooter, set in the near future during a period of planetary colonization. Drawing inspiration from classical military conflicts of the 20th century, Killzone demonstrates a unique graphical style that captures the grit and realism of intense military warfare. Featuring online gameplay via the Network Adaptor (Ethernet/modem) (for PlayStation®2) with voice-chat capabilities via the USB Headset (for PlayStation®2), Killzone is based on classic military altercations found in the history of warfare; players will battle through trenches, endure city sieges, sweat through jungles and battle guerilla combatants.

"Killzone will make fans of first-person shooters look at the genre in an entirely different way," said Ami Blaire, director, product marketing, Sony Computer Entertainment America. "Killzone is a game that delivers unique off- and online gameplay through an engrossing storyline, unbelievable graphics, great characters and an awesome array of weapons. As in every epic war story, Killzone also delivers a bad guy that everyone is going to love to hate: the Helghast."

The storyline behind Killzone occurs sometime in the near future on the nearby colony of Vecta, one of the interplanetary colonies that humans have established outside of Earth. An invading militaristic separatist faction called the Helghast has set out to decimate the ISA forces and colonize the planet. The only thing standing between the colony's survival and complete destruction is an elite squad of human ISA forces. Players can select between four ISA troops - each with special abilities and weaponry to accommodate their playing style - and battle through 11 intricately detailed environments that showcase the harsh setting of a war-ridden planet. Additionally, players can visit the armory and equip themselves with 27 different unique weapons. In particular, there are 21 first-person weapons that the player can carry, five emplaced weapons, and hand grenades.

Killzone employs a highly advanced artificial intelligence technology that allows Helghast enemies to calculate threats, maintain squad directives and adhere to self-preservation tactics to determine a unique course of action. Killzone also features an original score performed by the Prague Philharmonic Orchestra and Chorus.