An online co-operative expansion for Killzone, dubbed Shadow Fall Intercept, is coming to Playstation 4 on June 24. The add-on will be free for season pass holders. The expansion was announce during Sony's E3 conference on Monday. A standalone version of the game will be available August 5. During the conference, Sony said the four-player game lets users adopt distinct roles on four new maps. It includes new challenges, trophies, bosses, abilities and bonuses, as well as leader boards.