- One Lonely Outpost – v0.9.11a022-c4afe (v1.0 Release) + Bonus Soundtrack
- One Military Camp – v1.0.0.0 (Release)
- One More Dungeon 2 – v1.0.3
- One More Gate: A Wakfu Legend – Complete Edition, v1.1.1.1429 + 3 DLCs
- One More Night + Windows 7 Fix
- ONE PIECE ODYSSEY: Deluxe Edition + 6 DLCs
- One Piece Pirate Warriors 3: GOLD Edition + All DLCs
- One Piece: Burning Blood – Gold Edition (All DLCs)
- One Piece: Pirate Warriors 4 – Ultimate Edition – v1.0.8.0 + 17 DLCs
- One Piece: Unlimited World Red – Deluxe Edition
- ONE PIECE: World Seeker – v1.4.0 + 17 DLCs
- One Sole Purpose
- One True Hero – v1.0.1d
- Onechanbara Z2: Chaos
- Onee Chanbara ORIGIN: Deluxe Edition – v1.04 + 96 DLCs
- Onimusha: Warlords
- ONINAKI + DLC
- Onirike
- Only After
- Only One + Windows 7 Fix
- Only Up! + Windows 7 Fix
- Ooblets – v1.0.24_e_da + Windows 7 Fix
- Open Country – v1.0.0.2636
- Open Roads
- Open Wheel Manager 2
- Operation Wolf Returns: First Mission – Build 12197373
- Operation: Polygon Storm – Deluxe Edition + DLC
- Operencia: The Stolen Sun – Explorer’s Edition
- Oppcium
- Opus Magnum – Build 7993169 (01.17.2022)
- OPUS: Echo of Starsong – Full Bloom Edition, v2.5.6 + Bonus Content
- Orange Cast: Sci-Fi Space Action Game – v.20
- orbit.industries – v1.1.9537.0
- Orcs Must Die! 3: Complete Bundle – v1.2.0.0 + 3 DLCs + Multiplayer
- Orcs Must Die! Deathtrap – v1.1.2 + Supporters Pack DLC
- ORDER 13 – v1.02 (5038)
- Order of Battle: World War II – v9.0.6 + 16 DLCs
- Orders of Magnitude – v1.0 (Release)
- Orders of the Ruler
- Organs Please: Deluxe Edition – Build 10949045 + Bonus Content
- Ori and the Blind Forest
- Ori and the Blind Forest: Definitive Edition
- Ori and the Will of the Wisps
- Oriental Valley: Deluxe Edition + 2 DLCs + Windows 7 Fix
- Orten Was The Case
- Osiris: New Dawn – v0.5.616 (Release)
- Othercide – v7.75 + DLC + Bonus Content
- OU + Bonus Soundtrack
- Our Adventurer Guild – v1.071
- Our Life: Beginnings & Always – v1.6.0 + 7 DLCs