The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- Cellius (Developer) (1 member)
- Certain Affinity (Developer) (1 member)
- Cherry Pop Games (Developer) (1 member)
- Cherry Pop Games (Publisher) (1 member)
- Chunsoft (Developer) (1 member)
- Chunsoft (Publisher) (1 member)
- Cipher Prime (Developer) (2 members)
- Cipher Prime (Publisher) (1 member)
- City Interactive (Developer) (5 members)
- City Interactive (Publisher) (5 members)
- Clap Hanz (Developer) (3 members)
- Class of Heroes (Series) (2 members)
- ClassiC Shikoukairo (Developer) (1 member)
- Clever Beans (Developer) (1 member)
- Climax Studios (Developer) (2 members)
- Clocks scale (Config) (0 members)
- Co-op (Game mode) (369 members)
- Code Mystics (Developer) (1 member)
- Codeglue (Developer) (1 member)
- Codemasters (Developer) (17 members)
- Codemasters (Publisher) (27 members)
- Coffee Stain Studios (Developer) (2 members)
- Cohort Studios (Developer) (6 members)
- ColdWood Interactive (Developer) (3 members)
- Cold Beam Games (Developer) (1 member)
- Cold Beam Games (Publisher) (1 member)
- Combat flight simulator (Genre) (22 members)
- Comcept (Developer) (1 member)
- Command & Conquer (Series) (2 members)
- Compile Heart, Red Entertainment (Publisher) (1 member)
- Compile Heart (Developer) (10 members)
- Compile Heart (Publisher) (12 members)
- Compulsion Games (Developer) (1 member)
- Configurations (79 members)
- Console exclusive (Release type) (548 members)
- Corecell Technology (Developer) (2 members)
- Coreplay (Developer) (1 member)
- Coresoft (Developer) (1 member)
- Costume Quest (Series) (2 members)
- Covers (830 members)
- Crafts & Meister (Developer) (3 members)
- Crash Time (Series) (2 members)
- Crave Entertainment (Publisher) (4 members)
- Creat Studios (Developer) (16 members)
- Creat Studios (Publisher) (10 members)
- Creative Assembly (Developer) (4 members)
- Creative Vault Studios (Developer) (1 member)
- Crispy's! (Developer) (1 member)
- Crispy's (Developer) (1 member)
- Criterion Games (Developer) (4 members)