- Open The Classic Door Season 3
- Open World Madout Mafia City
- Open World Rope Hero
- Opening day of a fresh baker’s
- Operate Snow Excavator Crane
- Operation February
- Operation Helix
- Operation Mindfall 2.0
- Operation: Survive Runner 3D
- Operação Abaporu
- Ophidia
- Optical Inquisitor Zero
- OPUS: Rocket of Whispers
- Orbit 2D
- Orbit Drift - Space Explorer
- Orbit HD
- Orboot Dinos AR by PlayShifu
- Orboot Earth AR by PlayShifu
- Orboot Mars AR by PlayShifu
- Orc Escape
- Orca Simulator
- Ord.
- Ord.
- Ordesa - the interactive movie
- Ordia
- Organ Trail: Director's Cut
- Orikon Battle Mobile
- Orna: A Fantasy RPG & GPS MMO
- OROCHI in the HELL
- Orwell's Animal Farm
- Orwell: Keeping an Eye on You
- Os Caçadores de Lendas
- Oscar Adventure
- Oscar Collects Coin
- Oscar's Bubbles
- Oscar's Treasure Hunt
- Osman Gazi
- Osman Ghazi Warrior Legend
- Osman Ottoman Empire Warrior
- Osmo Coding Awbie
- Osmo Detective Agency
- Osmo Words Explorers
- OSSAN Eggs! mini -Spring Ver.-
- OSSAN Eggs! mini -Summer Ver.-
- OSSAN Eggs! mini -Winter Ver.-
- OsterGlück Gütersloh
- Ostrov Kostrov
- Otano Princess!
- Otomania
- Otto Matic
- Our Last Journey
- Out of The Box: Mobile Edition
- Outbreak: The Zombie Slayer
- Outer-Space
- Outfit Challenge
- Outlands Survival
- Outlaw Gliders
- Outlaw Tales Online Survival3D
- Outrun da Rail
- Outside World
- Outsider: After Life
- Over The Bridge PRO
- Over the Moon...
- Overboard!