Games Starting With "O"
Browse 530 games starting with "O" — all free, pre-installed, and ready to play.
- Oaken (v1.0.4)
- Oaken Tower (v0.4 & ALL DLC)
- Oakenfold (v1.0)
- Oakwood
- OASIS: Tokyo
- Oaths of Light - Chapter I
- Obama Boss Fight
- Obduction (v1.8.4.1)
- OBEN
- Obenseuer (v0.4.17)
- Obey the Insect God (v2026.04.11)
- Obey the Voice
- Objects in Space (v1.0.7)
- Oblin Party (v1.0.9)
- Obliteracers (v1.0.0.3640)
- Oblivion Eagle (v1.0)
- Oblivion Override (v1.1.2.1577)
- Oblivity - Find Your Perfect Sensitivity
- Obludia (v2014.12.23)
- Obnulenie (v1.0 & Uncensored)
- OBSCURA (v2.5.1 & R18)
- Obscurant (v1.0.1)
- Obscure
- Obscure II (Obscure: The Aftermath)
- Obscuritas (v1.2.1)
- Obscurite Magie 3: The Divine Stones (v1.02 & Uncensored)
- Obscurite Magie: The Blood Of Kings (v1.03 & Uncensored)
- Obscurite Magie: The City Of Sin (v1.01)
- Observation (v1.17)
- Observer: System Redux
- Observo
- Obsessed : Night Shift (v3.3.3)
- Obsideo (v2022.01.16)
- Obsidian Prince (v1.0)
- Occlude (v2.0.3)
- Occult
- Occupation 2.5
- Occupy Mars: The Game (v1.1.38)
- Ocean Is Home : Island Life Simulator (v0.7023)
- Ocean Planet (v1.25 & ALL DLC)
- Ocean Pressure
- Ocean Punk (v1.5.9.7)
- Ocean's Heart (v1.0.2)
- Oceaneers (v0.1.4o)
- Oceanhorn 2: Knights of the Lost Realm
- Oceanhorn: Chronos Dungeon (v1.0)
- Oceanhorn: Monster of Uncharted Seas
- OCO (v1.5146)
- Octavio Camacho
- Octodad: Dadliest Catch (v1.2.17060)
- Octogeddon (v2019.05.16)
- OCTOPATH TRAVELER 0
- OCTOPATH TRAVELER (v2020.07.22)
- OCTOPATH TRAVELER II (v1.1.0)
- Odallus: The Dark Call (v1.1.3)
- Odd Dorable
- Odd Realm (v1.0.36.0)
- Odd Remedy (v0.2.6.1 & Multiplayer)
- ODDADA (v1.1.1)
- ODDCORE (v2026.02.04)
- OddFauna : Secret of the Terrabeast (v0.1.1)
- Oddsparks: An Automation Adventure (v1.0.S30972 & ALL DLC)
- Oddworld: Abe's Exoddus (GOG)
- Oddworld: Abe's Oddysee
- Oddworld: Munch's Oddysee
- Oddworld: New 'n' Tasty (Complete Edition)
- Oddworld: Soulstorm Enhanced Edition
- Oddworld: Stranger's Wrath HD
- Odinfall (v0.5.1.3)
- Odium To The Core
- Ody Mos (v009 & Uncensored)
- Odyssey Of Gianna (Uncensored)
- Oedo Trigger!! (v1.0.5 & R18)
- Of Ash and Steel (v1.08)
- Of Bird and Cage (v2022.06.24)
- Of Blades & Tails (v1.1.5)
- Of Lies and Rain
- Of Life and Land (v2026.03.19)
- Of Mice and Moggies (v2021.11.14)
- OFF
- Off The Record: The Linden Shades Collector's Edition
- Off-Balance: Balance Party Vol. 2
- Off-Road Drive (v1.1.1.0)
- OFFBEAT (v1.0.3)
- Office Elevator
- Office Fight
- Office is My Harem (Uncensored)
- Office Lovers
- Office Management 101 (v0.6.4)
- Office Simulator (v1.2.0)
- Offroad Horizons: Arcade Rock Crawling
- Offroad Mania (v1.0.34)
- Offroad Mechanic Simulator (v1.06)
- Offroad Truck Simulator: Heavy Duty Challenge
- Offworld Trading Company (v1.23.68800 & ALL DLC)
- Ogre Chambers 2222
- Ogre Tale (v1.03)
- Ogu and the Secret Forest (v1.4 & ALL DLC)
- OH DEMON! Fix my TV
- Oh My God! Crush!
- Oh So Hero! (v0.24.001 & Uncensored)
- Oh! Edo Towns (v2.14)
- Oh...sir!! The Insult Simulator (v1.11)
- OHV (v2026.01.22)
- Oil Empire (v2026.03.28)
- Oirbo (v1.0.5)
- Ojiv (v2024.03.07 & Uncensored)
- OK K.O.! Lets Play Heroes (v1.0.0.159)
- Okaeri (v1.0)
- Okami HD
- Okhlos: Omega (v2.1.0)
- Okinawa Rush (v1.4)
- OK👍 Boomer
- Old Coin Pusher Friends 2 (v1.2.4)
- Old Coin Pusher Friends 3 (v1.0.1)
- Old Gods Rising (v2021.06.14)
- Old Man's Journey (v2018.05.25)
- Old Market Simulator (v2.1.4)
- Old School (v1.23)
- Old School Musical (v1.3.0)
- Old School Rally (v1.0.988)
- Old School RPG (v2024.08.13)
- Old Skies (v1.1)
- Old Stories: Fireheart (v1.0)
- Old World (v1.0.83499 & ALL DLC)
- Olija (v2022.11.07)
- Ollie-Oop
- OlliOlli
- OlliOlli World (v2025.10.03 & ALL DLC)
- OlliOlli2: Welcome to Olliwood (v1.0.0.7)
- Olympic Games Tokyo 2020 - The Official Video Game
- Omega Crafter (v1.0.5)
- Omega Labyrinth Life (Incl. DLC's)
- Omega Luma: The First Battle
- Omega Mouse Zero
- Omega Quintet (Incl. ALL DLC)
- Omega Strike (v1.0.1)
- OmegaBot
- Omelet You Cook (v1.0.10)
- Omen Exitio: Hunger
- Omen Exitio: Plague (v2.5.0f7)
- Omensight: Definitive Edition (v1.04)
- Omerta - City Of Gangsters (Incl. ALL DLC's)
- Omikron: The Nomad Soul (GOG)
- Omitted
- Omni Blade
- OmniFootman
- Omno
- OMORI (v1.0.8)
- OMSI 2: Steam Edition (Incl. ALL DLC's)
- Omurice Next Time (v1.0)
- On A Roll
- On Air Island : Survival Chat
- On Dark Terms
- On My Own
- On Target VR Darts
- On the Peril of Parrots (v1.0.0e)
- On the Road - Truck Simulator (v1.2.0.73)
- On the Run: Rogue Heroes
- On the Western Front (v2026.04.05)
- On the Wings - Birth of a Hero (v1.0)
- On Your Hands (v5.0)
- On Your Tail (v1.1.6)
- Once a Pawn a King
- Once a Porn a Time (Uncensored)
- Once Again
- Once Alive (v1.0.0.B11)
- Once Glorious Artahk (v1.3.1)
- Once in Flowerlake
- Once Upon a Dungeon - Infinity (v0.9.18.0)
- Once Upon a Dungeon II (v0.9.10.4)
- Once Upon A Jester
- Once Upon A KATAMARI
- Once Upon A Mind - A Little Too Friendly
- Once Upon a Puppet (v2.14.4.2 & ALL DLC)
- Onde (v1.5.0)
- One Boss One Fight (v1.0)
- ONE BTN BOSSES (v1.0.1)
- One Circle
- One Day In London
- One Deck Dungeon (v1.6.4)
- One Deck Galaxy
- One Dog Story (v2021.01.25)
- One Dreamer (v1.0.7)
- One Eleven (v1.3)
- One Fateful Night
- One Finger Death Punch 2 (v2020.02.26)
- One Finger Death Punch (v1.3)
- One Gun Guy
- One Gun: Cat
- One Hand Clapping (v1.0.41)
- One Iced Latte With Your Breast Milk, Please! (v1.25.9.11 & Uncensored)
- One Last Breath
- One Last Clip
- One Last Crane (v1.0.0)
- One Last Dinner
- One Last Memory - Reimagined
- One Last Raid
- One Last Toast (v1.8)
- One Late Night: Deadline (v1.1)
- One Line: Letters and Codes
- One Lonely Outpost (v0.9.11)
- One Long Night With the Circleheads (v1.0)
- One Mans Trash (v1.3.3)
- One Military Camp (v1.1.0.39 & ALL DLC)
- One More Dungeon 2 (v0.7.0)
- One More Dungeon (v1.2.1)
- One More Gate: A Wakfu Legend (v2024.05.24 & ALL DLC)
- One More Island (v1.8.1)
- One More Line
- One More Night
- One Move Away
- One Night ~Young Bride for One Night~ (v1.10 & Uncensored)
- One Night Stand (v2.282)
- One Night With Kawaii
- ONE PIECE BURNING BLOOD (v1.09 & ALL DLC)
- ONE PIECE ODYSSEY Deluxe Edition (v2.01 & ALL DLC)
- ONE PIECE PIRATE WARRIORS 3 (Incl. ALL DLC's)
- ONE PIECE WORLD SEEKER (v1.4.0 & ALL DLC's)
- ONE PIECE: PIRATE WARRIORS 4 (v2026.01.21 & ALL DLC)
- ONE PIECE: UNLIMITED WORLD RED - DELUXE EDITION (v2017.10.25)
- One Potion Please (v0.4.12 & Uncensored)
- ONE PUNCH MAN: A HERO NOBODY KNOWS (v1.300 & DLC)
- One Room Dungeon (v1.0)
- One Socket (v0.5.0.9)
- One Step After Fall
- One Step From Eden (v1.8.2)
- One Strike Definitive Edition
- One Tank Army
- One True Hero (v1.0.1d)
- One Turn Kill
- One Way Heroics (v2.22 & ALL DLC)
- One Way: The Elevator
- One-Eyed Likho
- ONE.
- Onechanbara Z2: Chaos (v1.09 & ALL DLC)
- Onee Chanbara Origin (v1.03 & ALL DLC's)
- Oneiric
- Oneiro (v1.3c)
- OneShot (v2022.12.06)
- OneShot: World Machine Edition (v1.24.12.22.0)
- OneShotRogue (v2022.08.24)
- oneway.exe: Module 1.0 (v2025.11.06)
- Oni (v1.0)
- Oni Onsen (v1.2.1 & Uncensored)
- Oni Station (v1.2.0)
- ONI: Road to be the Mightiest Oni
- ONIBITO KIKI
- Onigiri Shop Simulator (v1.2.6)
- Onigokko! (v1.00 & Uncensored)
- Onikira - Demon Killer
- Onimusha 2: Samurai's Destiny
- Onimusha: Warlords (v2023.07.10)
- Oninaki
- Onion Assault (v2023.02.01)
- Onirike (v1.0.10)
- Onirism (v1.0)
- Onka (v1.1.0)
- Only A Dream
- Only After
- Only Ban! (v1.0)
- Only Climb: Better Together (v2023.07.27)
- Only Down (v2023.08.04)
- Only Lead Can Stop Them (v1.16)
- Only One
- Only One Way Up
- Only Up 2
- Only Up: BRAINROT TOGETHER
- Only Up: LIZARDS MUST FALL (v1.0.4.3)
- Only Up: SKIBIDI TOGETHER (v1.4)
- Only Up! (v2023.07.07)
- Only Way is Down
- OnlyFap Simulator 2 (Uncensored)
- OnlyFap: Fitness Baby
- OnlyFuck - Ruru's Adventures (v1.15 & Uncensored)
- OnlyFuck 2: Scarlett (Uncensored)
- OnlySluts: WAIFU MATCH (Uncensored)
- Onsen Master
- Ooblets (v1.4.43)
- Ooglians (v0.0.32)
- Öoo
- Oops, I Said Yes?!
- Oops.. Where's My Bikini?! (Uncensored)
- Ooze Keeper (v1.3.0)
- Opaloid Kingdom (v2023.05.13)
- Open At Nine (Uncensored)
- Open Country (v1.0.0.2703)
- Open Door
- Open Hexagon (v2.1.7)
- Open Roads
- Open The Gates! (v1.0.6)
- Open Wheel Manager 2 (v2024.12.17)
- OpenTTD (v15.3)
- Operation Abyss: New Tokyo Legacy
- Operation Babel: New Tokyo Legacy
- Operation Body Count
- Operation Darkside DX (v2.6 & Uncensored)
- Operation Flashpoint: Dragon Rising
- Operation Lovecraft: Fallen Doll (v0.4.9 & Uncensored)
- Operation Night Strikers
- Operation Osama Bin Laden
- Operation STEEL (v1.4.1)
- Operation Thunderstorm (v1.0)
- Operation Warcade VR
- Operation: Polygon Storm (v0.9.9.9.7.1 & ALL DLC)
- Operation: Tango (v2.01.03 & Multiplayer)
- OPERATOR (v0.08.4431)
- Operencia: The Stolen Sun (v1.3.8)
- Operius DX
- OPPAI Academy Big, Bouncy, Booby Babes! (Uncensored)
- OPPAI Ero App Academy Bigger, Better, Electric Boobaloo!
- Oppai Odyssey (v0.4.0 & Uncensored)
- Oppai Samurai: Knocked Up By A No Name Novice (v1.2.5 & R18)
- OPPAI Succubus Academy Sucky and Busty, Demonic and Lusty! (Uncensored)
- Opus Magnum (v2026.03.31 & ALL DLC)
- OPUS: Echo of Starsong - Full Bloom Edition (v2.5.6)
- OPUS: Prism Peak (v1.34.5.82 & ALL DLC)
- OPUS: Rocket of Whispers (v4.8.1)
- OPUS: The Day We Found Earth (v3.5.3)
- Oracle Of Forgotten Testament
- Orange Cast: Sci-Fi Space Action Game
- Orange Roulette
- Orange Season (v1.0.2)
- Orangeblood (v01.14.2020)
- Orb of Creation (v1.0.3.3)
- Orb Tower
- Orbals (v1.0)
- OrbHand (v1.0)
- Orbi Universo (v1.7.2)
- Orbi Universo II (v1.3.5a)
- Orbit - Playing With Gravity
- Orbit.industries (v1.1.9717.0)
- Orbital Bullet – The 360° Rogue-lite (v1.1.0)
- Orbitect (v0.9.7f3)
- Orbitmine (v2026.08.07)
- Orbo's Odyssey (v1.1.3)
- Orbs of Chaos (v0.2.1.1)
- OrbWars (v1.0)
- Orbyss (v2025.12.21)
- Orc Colony (v0.3.1)
- Orc Massage (v2023.07.11 & Uncensored)
- Orc Survivors
- Orcs Must Die! 2 (Incl. ALL DLC)
- Orcs Must Die! 3 (v1.2.5.7 & ALL DLC)
- Orcs Must Die! Deathtrap (v2.0 & ALL DLC)
- Orcs Must Die! (Incl. ALL DLC)
- Ordeal Of Princess Eris (v1.01 & Uncensored)
- ORDER 13 (v1.1)
- Order of Battle: World War II (v10.0.6 & ALL DLC)
- Order Of War
- Orderly Havoc (v1.0.1)
- Ore Factory Squad (v1.0.7)
- Orebound (v0.0.0.71y)
- Organ Trail: Director's Cut
- Organized Inside (v1.5.0)
- Organs Please (v1.0)
- Orgasm Lab Simulator (Uncensored)
- Orgasm Simulator 2023 (Uncensored)
- Ori And The Blind Forest Definitive Edition
- Ori and the Will of the Wisps (v2020.11.19)
- Oriental Empires (v1.0.1.16)
- Oriental Valley (v1.0 & ALL DLC)
- Origament: A Paper Adventure (v1.8.1)
- Origami Lovers
- Orion Sandbox Enhanced (v2018.10.01)
- Orph - The Lost Boy
- Orten Was The Case
- Orwell: Ignorance is Strength (v1.1.9207.35014)
- Orwell: Keeping An Eye On You (v1.2.6488.25073)
- Orwell's Animal Farm (v2020.12.21)
- ORX (v0.13.2.12)
- OshiRabu: Waifus Over Husbandos ~Loveordie~
- OshiRabu: Waifus Over Husbandos
- Osiris: New Dawn (v0.5.616)
- Osman Gazi (v2025.01.05)
- Ossuary (v2022.04.09)
- Osta
- Ostalgie: The Berlin Wall (v2.5.09 & ALL DLC)
- Osteoblasts (v1.0)
- Ostranauts (v1.0.0.7)
- Ostrich Farm (v1.0.1)
- Ostriv (v0.5.9.58 & ALL DLC)
- Otaku's Adventure (v1.3.0)
- Other Side of Mist and Mountain (v0.6.15)
- Othercide (v7.77 & ALL DLC)
- Otherskin
- OtherSoul
- Otherworld Legends (v2.8.1 & ALL DLC)
- Otherworldly Air Gunship (v2.0)
- Otoko Cross: Pretty Boys Dropout! (v1.0 & Uncensored)
- Otoko Cross: Pretty Boys Mahjong Solitaire (v1.0.0)
- Otome * Domain
- Otome Legends
- Otome The Exorcist (v1.00 & Uncensored)
- OTXO (v1.05)
- OU
- Ouction (Uncensored)
- Ouija Rumours
- Our Adventurer Guild (v1.7 & ALL DLC)
- Our Darker Purpose (v480.1.11)
- Our Home
- Our Home, My Keeper (v2026.04.30)
- Our Land
- Our Life: Beginnings & Always (v1.7.1 & ALL DLC)
- Our Lovely Escape (Incl. Mature Content)
- Our Past
- Our Red String (Chapters 1-11 & Uncensored)
- Our Secret Below (v1.4.7)
- Our Summer Festival
- Our Two Bedroom Story (v2023.12.19)
- Our War: Firepower Suppression (v1.0)
- Our World is Ended.
- Ourlands (v1.0.15)
- Ouros (v1.0.1)
- OURWORLD
- Out and About (v0.1.7)
- Out of Action (v2026.08.08)
- Out of Bounds
- Out of Hands (v1.0)
- Out of Line (v1.0.1.2)
- Out Of Mind
- Out of Orbit (v0.6.9)
- Out of Ore (v0.33.4463 & ALL DLC)
- Out of Sight [NinjaDuck Games]
- Out of Sight [The Gang] (v1.0.48)
- Out of Space (v1.2.4b13)
- Out of the Box
- Out of the Ocean
- Out Of The Park Baseball 22
- Out of the Park Baseball 23 (v23.1)
- Out of the Park Baseball 24 (v24.7)
- Out of the Park Baseball 25
- Out of the Park Baseball 26 (v26.1)
- Out of the Park Baseball 27
- Out There: Oceans of Time (v1.2.1.2 & ALL DLC)
- Out Zone
- Outbound (v1.1.7.961 & ALL DLC)
- Outbreak 2030
- Outbreak Island (v2026.03.28)
- Outbreak The Fedora Files: What Lydia Knows
- Outbreak: Contagious Memories
- Outbreak: Shades of Horror Chromatic Split
- OUTBRK (v0.0.3.593)
- OUTBUDDIES DX (v2020.07.26)
- Outcast - A New Beginning
- OutDrive
- Outer Terror (v1.2)
- Outer Wilds (v1.1.16 & ALL DLC)
- Outerverse (v2022.08.25)
- Outhold (v1.1.8)
- Outlanders (v2025.05.26 & ALL DLC)
- Outlast + Whistleblower DLC
- Outlast 2
- Outlaws + A Handful Of Missions (GOG)
- Outlaws + Handful of Missions: Remaster
- Outlive 25 (v2.26.0429)
- Outlive
- Outliver: Tribulation
- Outpath (v1.0.15a)
- Outpost
- Outpost On Syrinx
- Outpost: Infinity Siege - Vanguard Edition (v2024.06.07)
- Outrider Mako (v1.396.3)
- OutRun 2006: Coast 2 Coast
- Outshine (v0.24.3)
- Outside The Blocks
- Outside The Box (Uncensored)
- outside the door (v1.0)
- Outsider: After Life
- OUTSTAND
- Outward Definitive Edition (v1.1.0)
- Outward (v06.02.2021 & ALL DLC's)
- Outworld Station (v1.0.0.4)
- Ova Magica (v1.01)
- OVE : The Sword Of Liberation
- Over Heroes
- Over Islands (v2.0)
- Over The Alps
- Over The Top: WWI (Incl. Multiplayer)
- OVER THE TOWER
- OVER‧DeviL: Legend of the Sacred Stone (Uncensored)
- Overboard! (v1.4.1)
- Overboss (v1.0)
- Overbowed (v2025.03.15)
- Overcooked: Gourment Edition
- Overcooked! 2 (v6.231 & ALL DLC)
- Overcooked! All You Can Eat (v2023.02.16)
- Overcrowd: A Commute 'em Up (v1.0.42)
- Overdriven Reloaded (v2.7.29 & ALL DLC)
- Overdungeon (v1.3.0 & ALL DLC)
- Overgrown: Genesis (v1.00.0 & Uncensored)
- Overgrowth (v1.4.0)
- Overhaul
- Overkill's The Walking Dead
- Overland (v2020.10.29)
- Overlay Studio
- Overload (v1.0)
- Overloop (v1.1)
- Overlooting (v2026.02.25)
- Overlord (Incl. Raising Hell)
- Overlord II
- OVERLORD: ESCAPE FROM NAZARICK (v1.0.7)
- Overmorrow
- Overpass [Studio Bean] (v1.1.1)
- Overpass 2 (Incl. ALL DLC)
- OVERPASS Deluxe Edition [Zordix Racing]
- Override 2: Super Mech League (Incl. ALL DLC)
- Override: Mech City Brawl (v2019.04.12 & ALL DLC)
- Overrogue
- OveRRooT
- Overthrown (v2025.04.03)
- Overtime Anomaly (v2025.03.28)
- Overtime Heroes Exit 8 (v1.0.1)
- Overture (v4.0.7)
- OVERWHELM (v2021.11.19)
- OVIS LOOP (v0.4.1)
- OVIVO
- Owinka Shooter 2
- Owl Lights
- Owlboy (v1.3.6613)
- Oxenfree (v2.7.0)
- OXENFREE II: Lost Signals (v1.4.8)
- Oxide Room 104
- Oxygen Cocktail
- Oxygen (v1.025)
- Oxygen Not Included (v744825 & ALL DLC)
- Oxytone (v1.1.3)
- OYASUMII (v1.0.1)
- OZMAFIA!! (v2016.04.30)
- Ozymandias: Bronze Age Empire Sim (v1.5.0.10 & ALL DLC)