Killzone: Mercenary

For the first time in a Killzone campaign, players can fight alongside Helghast forces as well as ISA specialists, carrying out missions that regular soldiers cannot. As a mercenary, players are free to decide which tactics and load outs they will use to fulfill their contract; employers will reward players with money if successfully completed. The game utilizes the PS Vita's touchscreen and rear touch panel.

Killzone: Mercenary takes place on the planets Vekta and Helghan, locked in an interstellar war. The game is set in between Killzone 2 and Killzone 3 and revisits many of the key events of Killzone, Killzone: Liberation, and Killzone 2 from the perspective of Arran Danner, a mercenary hired to execute operations for the ISA. He is supplied by mysterious weapons dealer Blackjack, and is aided at times by his boss Anders Benoit.

The game starts with the Helghast invasion of Vekta. Mercenaries Arran Danner and his partner Damian Ivanov are tasked by their boss – Anders Benoit to arrive in the Vektan city of Diortem on a mission to rescue ISA Admiral Alex Grey from Helghast forces using location information gained by the Vektan Ambassador – Sepp Harkin. Danner and Ivanov fight their way through the Vektan Halls of Justice where she is being held. They witness Helghast Colonel Kratek attempting to execute her, but manage to extract her safely.

At Gamescom 2012, it was revealed that the title is Killzone: Mercenary. The game utilizes a modified version of the Killzone 3 rendering engine, allowing volumetric lighting and smoke, high resolution environment textures, gleaming metal, and realistic-looking shadows. It was released in September 2013. Unlike previous Killzone installments, Mercenary was not developed by Guerrilla Games, but instead, their sister studio, Guerrilla Cambridge (formerly SCE Cambridge Studio). A senior producer at the studio said the production time was around less than two years after converting Killzone 3's engine.

In comparison to previous installments, Mercenary would offer "the series' biggest weapon loadout yet". Due to the larger weapon loadout, it accommodates a wider variety of play styles than in past Killzone games. Because of the refined damage model, the weapons apparently "feel slightly more powerful" than those in previous installments.

Killzone: Mercenary received "generally positive reviews", according to review aggregator website Metacritic. It managed to highly exceed the first two PS Vita first-person shooters, Call of Duty: Black Ops: Declassified and Resistance: Burning Skies, which both received fairly negative reviews. The game sold 11,053 copies in Japan within the first week of release. IGN called it "the best portable shooter ever made".

TheSixthAxis stated "there's no other experience like this on a device as small as this". It received the 1st Place 2013 PlayStation Vita Game of the Year Award.