Plot: Online Chess Kingdoms is a chess simulation game for the PlayStation Portable developed by American studio Leviathan Games and released by Konami in 2006 in North America and 2007 in Europe. Online Chess Kingdoms was the first chess game released for the PlayStation Portable. Wikipedia
Plot: Echoshift is a puzzle video game for the PlayStation Portable and PlayStation Vita systems. The game uses events known as Time Bounces in which a small section of time repeats itself over and over again. Wikipedia
Plot: PQ2: Practical Intelligence Quotient 2 is a puzzle game for the PlayStation Portable, and a sequel to PQ: Practical Intelligence Quotient. The game is based on testing the model of human intelligence developed by Dr. Masuo Koyasu at Kyoto University. Wikipedia