• One Aperture
• Onefurinthebox
• Ozark Softscape
• Oliver Chime
• Onur Vural
• Onur Vural and Leigh Christian
• Outplay Entertainment Ltd
• OneManTeam
• Overcurfew
• One Lives Left
• Orfeas Game Studio
• Outlaw Wars
• Oscar Celestini
• Omega Games
• One or Eight INC.
• Oneiric Entertainment LLC
• On The Wall Entertainment
• Oddly Shaped Pixels
• Oscar Kenneth Albero Ingles
• Open Sorcery Games
• Owlet
• OCP
• OpenWorldComics
• Over The Moon