Oddworld Adventures (USA, Europe)
Oira Jajamaru! Sekai Daibouken (Japan)
Olympic Summer Games (USA, Europe)
Oni II - Innin Densetsu (Japan)
Oni III - Kuro no Hakaishin (Japan)
Oni IV - Kijin no Ketsuzoku (Japan)
Oni V - Innin o Tsugumono (Japan)
Onigashima Pachinkoten (Japan)
Operation C (USA)
Osawagase! Penguin Boy (Japan)
Othello (Europe)
Othello (Japan)
Othello World (Japan)
Otogibanashi Taisen (Japan)
Otto's Ottifanten - Baby Bruno's Nightmare (Europe) (En,Fr,De,Es)
Out of Gas (USA)
Outburst (Japan)
Oyatsu Quiz Mogu Mogu Q (Japan)