| Adriano Gomes da Silva | Developer | |
| Adriano Silva | Developer | |
| Adriano Veríssimo | Developer | |
| Adridle | Developer | |
| Adrielus | Developer | |
| Adrien Poncet | Developer | |
| Adrián Bayardi | Developer | |
| Adrián Calvo | Developer | |
| Adrián Corbalán | Developer | |
| Adroit Conceptions | Developer | |
| Adtberp | Developer | |
| Adult Swim Games | Publisher | |
| Adure | Developer | |
| Adure Games | Developer | |
| Advance | Publisher | |
| Advance Communication Co. | Developer | |
| Advance Communication Company | Developer | |
| Advance Games | Developer | |
| Advance Reality Interactive | Developer | |
| Advance Software | Publisher | |
| Advanced Interactive Games | Publisher | |
| Advanced Productions | DeveloperPublisher | |
| Adventions | Publisher | |
| Adventuras AD | DeveloperPublisher | |
| Adventure International | DeveloperPublisher | |
| Adventure Islands | Developer | |
| Adventure Planning Service | Developer | |
| Adventure Productions | Developer | |
| Adventure Soft | DeveloperPublisher | |
| AdventureBit | Developer | |
| AdventureBox | Developer | |
| AdventureByte | Developer | |
| Adventurer32 | Developer | |
| Adventuron | Developer | |
| AdverDomina | Developer | |
| Ady Studios™ | Developer | |
| Adynod | Developer | |
| Aeclain | Developer | |
| Aedian Glair | Developer | |
| AedifexGames | Developer | |
| Aeg | Developer | |
| Aegis Interactive Entertainment | Publisher | |
| Aegix Drakan | Developer | |
| Aehersin | Developer | |
| Aekai | Developer | |
| Aekashics | Developer | |
| Aemetta | Developer | |
| Aemetta and toasteater | Developer | |
| Aemyn Connolly | Developer | |
| Aeon Electronic Entertainment | Developer | |