has taken Milcher and Stratson. Milcher is then killed by Cobar, but Jan is nevertheless successful in defeating him, even though Cobar was piloting a personal walking tank. Cobar reveals that there is a traitor in ISA command who is helping the Helghast, but is finished off by Stratson before he can say who the traitor is. The next step for Templar is to assault Metrac's mountain fortress and rescue Batton. Luger aids him on the mission. There, he fights many of Helghan's elite warriors (including a giant cybernetic unit) before encountering and killing Metrac in a final showdown. Afterwards, Templar locates Evelyn and escapes with her just before the fortress is destroyed. The game's outro marks the beginning of Killzone 2, as we hear Visari speaking of nuclear weapons which he intends to use on ISA forces. In the fifth, downloadable chapter, Jan is sent on a mission to the former Vektan capital of Sedah city. Even though Metrac is no more, the enemy forces are still coordinated and fighting well. ISA believes that the unknown traitor is supplying Helghan with information. The only suspect is Rico, Jan's friend. Battling his way through the war-ravaged city, Jan finally finds Rico, who reveals that the traitor is, in fact, Stratson, who not only sold the planet to Helghast, but has become the shadow commander of the remaining Helghan forces. Jan proceeds to the Royal Palace of Vekta, where Stratson is located, battling hordes of Helghast and even Stratson's personal elite guard on his way. There, he engages the general in combat. However, Stratson is well-prepared and uses his armored mecha against Jan, but is ultimately defeated. He, wounded, is then arrested by ISA forces. Development Housemarque provided coding support for the game. Release The game was originally intended to have downloadable content (DLC) on its release day, but due to technical difficulties, the downloads promised were initially undelivered. On May 30, 2007, the free downloadable upgrade was released. The upgrade included two additions: Online multiplayer support including two new multiplayer maps and a new multiplayer game mode. Chapter 5 of the single-player campaign which concludes the game storyline. As of 2011, the two DLC files were no longer available from the Killzone website. In June 2011, because of the "Welcome Back" operation, Guerrilla republished the DLC for the US and EU version. Reception The game received "generally favorable reviews" according