The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- Incinerator Studios (Developer) (3 members)
- Incognito Entertainment (Developer) (2 members)
- Incorrect IRD parameter (GameID) (44 members)
- Incorrect configurations (Config) (1 member)
- Incorrect game mode parameter (Infobox) (0 members)
- Incorrect release type parameter (Infobox) (0 members)
- IndiePub (Publisher) (1 member)
- IndiePub Entertainment (Publisher) (1 member)
- IndiePub Games (Publisher) (1 member)
- Infinite Dreams (Developer) (1 member)
- Infinite Dreams (Publisher) (1 member)
- Infinite Interactive (Developer) (3 members)
- Infinite Stratos (Series) (2 members)
- Infinity Ward (Developer) (5 members)
- Initial release year (14 members)
- Insomniac Games (Developer) (11 members)
- Interactive art (Genre) (7 members)
- Interactive drama (Genre) (2 members)
- Intergrow (Publisher) (1 member)
- Internal resolution (215 members)
- International Games System (Developer) (0 members)
- International Games System Co (Developer) (1 member)
- Inti Creates (Developer) (3 members)
- Irem Corp. (Developer) (6 members)
- Irem Corp. (Publisher) (4 members)
- Iron Galaxy (Publisher) (1 member)
- Iron Galaxy Studios (Developer) (3 members)
- Iron Man (Series) (2 members)
- Irrational Games (Developer) (2 members)
- Isopod Labs (Developer) (1 member)
- Ivent Games (Developer) (1 member)
- Ivent Games (Publisher) (1 member)
- JV Games (Developer) (1 member)
- JV Games (Publisher) (1 member)
- Jackbox Games (Developer) (2 members)
- Jackbox Games (Publisher) (2 members)
- James Bond (Series) (4 members)
- Japan (Release region) (778 members)
- Japan Studio (Developer) (17 members)
- Jellyvision Games (Developer) (1 member)
- Jikkyou Powerful Pro Yakyuu (Series) (7 members)
- JoJo's Bizarre Adventure (Series) (3 members)
- Joe Danger (Series) (2 members)
- Johnson-Voorsanger Productions (Developer) (2 members)
- JoyBits (Developer) (3 members)
- Joysound (Series) (1 member)
- Juice Games (Developer) (1 member)
- Just Add Water (Developer) (4 members)
- Just Dance (Series) (8 members)
- KMM Interactive Entertainment (Developer) (1 member)