Killzone Mercenary Developed by Guerilla Games Cambridge, Killzone: Mercenary game throws players into a deadly firefight as the ruthless Mercenary faction, taking on paid contracts not only from the dangerous ISA, but the vicious Helghast as well. Play through 9 massive single-player missions, each with additional challenges and special objectives. Built on the same Killzone engine used on PlayStation 3 system, Killzone: Mercenary has stunning visuals and the smooth gameplay shows off the PS Vita system like no other game. Intense combat for up to 8 players keeps the competition fierce. Customize your Mercs loadout in Campaign and Multiplayer modes with armor, weapons and more.