| Game title | |
|---|---|
| Obduction | 24 - 08 - 2016 |
| OBEY | 21 - 05 - 2015 |
| Obliteracers | 23 - 02 - 2016 |
| Oblitus | 27 - 02 - 2015 |
| Obscure 2 The Aftermath | 25 - 03 - 2008 |
| Observer | 15 - 08 - 2017 |
| Observer: System Redux | 10 - 11 - 2020 |
| Obulis | 19 - 03 - 2009 |
| Occupy Mars: The Game | 01 - 01 - 1970 |
| Oceanhorn: Monster of Uncharted Seas | 17 - 03 - 2015 |
| OCTAHEDRON | 20 - 03 - 2018 |
| Octodad: Dadliest Catch | 30 - 01 - 2014 |
| Octogeddon | 08 - 02 - 2018 |
| OddPlanet | 11 - 05 - 2016 |
| Oddworld: Abe's Oddysee | 31 - 08 - 1997 |
| Oddworld: New 'n' Tasty | 25 - 02 - 2015 |
| Oddworld: Soulstorm | 06 - 04 - 2021 |
| Ode | 27 - 11 - 2017 |
| Odium To the Core | 11 - 05 - 2018 |
| Odyssey - The Next Generation Science Game | 19 - 04 - 2017 |
| Of Bird and Cage | 20 - 05 - 2021 |
| Of Kings And Men | 25 - 08 - 2016 |
| OF MICE AND SAND -REVISED- | 28 - 03 - 2018 |
| Of Orcs and Men | 11 - 10 - 2012 |
| Off-Road Drive | 29 - 09 - 2011 |
| Offensive Combat: Redux! | 18 - 08 - 2017 |
| Offroad Transport Simulator | 01 - 01 - 1970 |
| Offspring Fling! | 11 - 05 - 2012 |
| Offworld Trading Company | 28 - 04 - 2016 |
| Ogre | 05 - 10 - 2017 |
| Oh My Godheads | 05 - 12 - 2017 |
| Oh...Sir! The Hollywood Roast | 31 - 05 - 2017 |
| Oh...Sir!! The Insult Simulator | 25 - 10 - 2016 |
| Oi, Innkeep! | 01 - 01 - 1970 |
| OK K.O.! Let's Play Heroes | 23 - 01 - 2018 |
| Okami HD | 12 - 12 - 2017 |
| Okhlos | 18 - 08 - 2016 |
| Old Man's Journey | 18 - 05 - 2017 |
| Old Time Hockey | 28 - 03 - 2017 |
| Old World | 05 - 05 - 2020 |
| Olija | 28 - 01 - 2021 |
| OlliOlli | 22 - 07 - 2014 |
| OlliOlli2: Welcome to Olliwood | 11 - 08 - 2015 |
| Olympia Rising | 23 - 07 - 2015 |
| Omensight | 15 - 05 - 2018 |
| Omerta: City of Gangsters | 31 - 01 - 2013 |
| Omni | 01 - 01 - 1970 |
| OmniBus | 26 - 05 - 2016 |
| Omno | 29 - 07 - 2021 |
| OMSI 2 | 11 - 12 - 2013 |