O2Jam NX
Oasis
Oberon Media LEGO Fever
Obitus
Obscure
Obscure 2
Obsidian
Ocean Trader
Oddballz
Oddworld: Abe's Oddysee
Oddworld 2: Abe's Exoddus
Odell Down Under
Odieu's Quest For The Magic Fling-Shot
Odium
O.D.T.
Odyssey
Odyssey: The Search For Ulysses
Odyssey, The: Winds Of Athena
Of Light And Darkness
Offense
Office, The
Official Formula 1 Racing
Official Hamster Republic RPG Creation Engine
Offical Team Manager
Offroad
Off-Road Redneck Racing
Oh No! More Lemmings
Oil Tycoon
Oil Tycoon 2
Oldtimer
Olympic Games
Omar Shariff Bridge 2
Omega Stone, The
Omikron: The Nomad Soul
Once Upon A Knight
On The Ball: League Edition
Onefog Xonix
One Must Fall 2097
One Must Fall: Battlegrounds
One Step Beyond
Oni
Onimusha: Warlords
Onimusha 3: Demon Siege
Ooops Up
Open Season
Opening Weekend: Big Cats Season
Opening Weekend: Deer Season
Opening Weekend: Varmint Season
OpenIt
Open Kart
Opera Fatal
Operation Air Assault 2
Operation Blockade
Operation Bodycount
Operation Carnage
Operation Crusader
Operation Desert Hammer
Operation Europe
Operation Flashpoint
Operation Flashpoint: Cold War Crisis
Operation Flashpoint: Red Hammer
Operation Flashpoint: Resistance
Operation Inner Space
Operation Matriarchy
Operation Meteoroid
Operation Spacehog
Operation Stealth
Operation Thunderbolt
Operation Tiger Hunt
Operation Wolf
Opplossing Eggerland 3
Opposition 3: Sudden Impact
O.R.B.
Orbs Of Attrition
Oregon Trail
Oregon Trail 2
Oregon Trail 3: 150th Anniversary
Origamo
Original War
Orion Burger
Orion Conspiracy
Ostrich Runner
Oscar
Osiris
Otto Matic
Outbound
Outbreak
Outbreakers
Outcast
Outcome
Outdoor Life Sportsman's Challenge
Outdoors Pro Hunter
Out Of This World
Out To Lunch 
Outer Ridge
Outforce
Outlaw Chopper
Outlaw Golf
Outlaws
Outliner
Outlive
Outpost
Outpost 2: Divided Destiny
Outrage
Outrun
Outrun 2006: Coast 2 Coast
Outwars
Over The Hedge
Overboard
Overboard!
Overdrive
Overkill
Overload
Overlord
Overlord (2007)
Overlord: Raising Hell
OverTower
Oxyd
Oxyd Extra
Oxyd Magnum
Oyakusoku Love
Oyomesan wa Mime Fujo