Ochainu Kururin (J)(Caravan)
Ochainu no Bouken Jima (J)(sUppLeX)
Ochaken No Heya (J)(Rising Sun)
Ochaken no Yumebouken (J)(Caravan)
Oddworld - Munch's Oddysee (U)(Rising Sun)
Ohanaya-san Monogatari (J)(GBANow)
Ohanaya-san ni narou! (J)(kaMX)
Ojaru Maru - Tsuki Hikari Machi Tour de Ojaru (J)(Trashman)
Okaitoku Series 5 - Puzzle & Tantei Collection (J)(Patience)
Okuman Chouja Game (J)(Independent)
One Piece - Mezase! King of Paris (J)(Cezar)
One Piece - Nanatsu Shima no Daihihou (J)(Cezar)
One Piece Dragon Dream (J)(Caravan)
One Piece Going Baseball (J)(Eurasia)
Onimusha Tactics (E)(Patience)
Onimusha Tactics (U)(Mode7)
Onimusha Tactics (J)(Eurasia)
Onmyou Taisenki Zeroshiki (J)(Caravan)
Open Season (E)(Sir VG)
Open Season (U)(Rising Sun)
Operation Armored Liberty (U)(Rising Sun)
Oriental Blue - Ao no Tengai (J)(Cezar)
Oshaberi Inco Club (J)(Chakky)
Oshare Princess (J)(Chakky)
Oshare Princess 2 And Doubutsu Kyaranabi (J)(Mugs)
Oshare Princess 3 (J)(Rising Sun)
Oshare Princess 5 (J)(Supplex)
Oshare Princess EX Primo Debut Monogatari & Renai Uranai Daisakusen (J)(Caravan)
Oshare Wanko (J)(Supplex)
Ottifanten Pinball (G)(Rising Sun)
