High Quality Content by WIKIPEDIA articles! Killzone is a series of first-person shooter and third-person shooter video games exclusively for Sony Computer Entertainment`s (SCE) video game consoles. The main series and the PSP installment was developed by Guerilla Games, a subsidiary of SCE. Killlzone currently consists of four games spanning over the PlayStation 2, the PlayStation Portable, and the PlayStation 3. The series began on the PlayStation 2 in November 2004 with Killzone, and continued on the PlayStation Portable in October 2006 with Killzone: Liberation. The next installment was Killzone 2, released for the PlayStation 3 in February 2009. The most recent installment is Killzone 3, released in February 2011 also for the PlayStation 3. Killzone: Mercenary is currently in development for the PlayStation Vita for a 2013 release.