Games starting with letter O
N64
Genesis 
SNES
NES
Sega
Omega Race
OutRun 2019
Out of this World
Outrun
Ottifants
Onslaught
OutRunners
Operation Europe - Path to Victory 1939-1945
Olympic Gold - Barcelona 92
Osomatsu Kun Hachamecha Gekijou - Mr. Chunga
Outlander
Olympic Winter Games - Lillehammer 94
Operation Secret Storm
Operation Wolf
Orb-3D
Othello
Over Horizon
Overlord
Obitus
Ogre Battle
Olympic Summer Games
On the Ball
Operation Logic Bomb
Operation Thunderbolt
Oscar
Out to Lunch
Off Road Challenge
Ogre Battle 64: Person of Lordly Caliber
Olympic Hockey Nagano '98
OutRun Europa
Olympic Gold
Oddworld: Munch's Oddysee
One Piece
Open Season
Operation: Armored Liberty
Our Breeding Series: My Beetle
Oriental Blue: Ao no Tengai
Over the Hedge
Over The Hedge: Hammy Goes Nuts!
Ozzy & Drix
Oddworld Abes Exoddus
Oddworld Abes Oddysee
O.D.T.
Olympic Soccer
One
Open Ice
Overboard
Onimusha Warlords
Off-World Interceptor
Obsidian
Odium
Of Light and Darkness: The Prophecy
Ominous Horizons: A Paladin's Calling
Oni
Operation Flashpoint
Operation Flashpoint Gold Edition
Outlaws
Outpost 2: Divided Destiny
Outwars
Odama
Outlaw Golf
Obscure
Oddworld: Stranger's Wrath
Otogi: Myth of Demons
Outlaw Golf 2
Outlaw Volleyball
Outrun 2
Okage: Shadow King
Okami
Onimusha 2: Samurai's Destiny
Onimusha 3: Demon Siege
Onimusha Blade Warriors
Onimusha: Dawn of Dreams
Orphen: Scion of Sorcery
Omega Boost
Online Chess Kingdoms
Ooga Booga
Orphen
Ogre Battle 64
Operation C
Oddworld Adventures
Olympic Summer Games: Atlanta 1996
Out of Gas
Outburst
Orge Battle: Limited Edition
Overblood
O'Leary Manager 2000
Oddworld Adventures 2
Oide Rascal
Other Life: Azure Dreams
Onimusha 3
Outlast
Oregon Trail II
Oregon Trail Deluxe