 Game developer Ready at Dawn pitched the idea of a God of War game for the PlayStation Portable to Santa Monica Studio soon after the original God of War launched . Cory Barlog officially confirmed the development of Chains of Olympus at a God of War II launch event , stating " It is its own story that connects to the overall story . " Chains of Olympus uses a proprietary , in @-@ house engine referred to as the Ready at Dawn engine , which expanded on the engine created for their previous game , Daxter ( 2006 ) . Originally designed for the PlayStation Portable 's restricted 222 megahertz ( MHz ) processor , Ready at Dawn convinced Sony to increase the clock speed of the PSP to 333 MHz , which they did in a firmware upgrade . The faster processor allowed for more realistic blood effects , lighting effects , and shadows as well as improved enemy intelligence , but noticeably decreased battery life . After the game 's completion , game director Ru Weerasuriya stated multiplayer options and other puzzles , characters , and dialogue had to be removed due to time constraints . 
