God of War: Chains of Olympus is a good PSP game. I always use the Efreet (R+Triangle) and Charon's Wrath (R+O), both used to burn your enemies. If your enemies are far from you or above you, use the Light of Dawn (R+Square). It's not really hard, you can finish the game in 5 hours, if you use Mortal mode, which is very easy. After beating the game, you unlock the challenges, in-game movies, God Mode (which is very hard) ,and the Spud Of War costume. Complete the five challenges and then you will unlock the McKratos costume. And if you beat the game in God mode, you will unlock the Mime of War.