| Astralore | Developer | |
| Astrid Dalmady | Developer | |
| Astridelta | Developer | |
| Astro | Developer | |
| Astro Lords Dev | Developer | |
| Astro Port | Developer | |
| Astro1 | Developer | |
| AstroBearGames | Developer | |
| AstroLabe | Developer | |
| AstroSocks | Developer | |
| Astrogun | Developer | |
| Astroillogica | Developer | |
| Astrojone | Developer | |
| Astroll | DeveloperPublisher | |
| AstrollJP | Publisher | |
| Astronation | Developer | |
| Astronaut Curve | Developer | |
| Astronauts | DeveloperPublisher | |
| Astronautz | Developer | |
| Astrophobia | Developer | |
| Astros Productions | DeveloperPublisher | |
| Astros Productions (Peter Karboulonis, George Karboulonis) | Developer | |
| Astrosaurus Games | DeveloperPublisher | |
| Astrovision | Developer | |
| Astucia | Developer | |
| Astus Games | Developer | |
| AstuteOne | Developer | |
| Asue | Developer | |
| Asuka Technologies | Developer | |
| Asuro | Developer | |
| Asylum Entertainment | DeveloperPublisher | |
| Asylum Square | Developer | |
| Asylum Square Interactive | Publisher | |
| Asylum studios | Developer | |
| AsylumSquad | Developer | |
| Asymetrical Pigeon | Developer | |
| Asymmetric Publications | DeveloperPublisher | |
| Asynchron | Developer | |
| AtKombi | Developer | |
| Ata Dogan | Developer | |
| Atapki | Developer | |
| Atara Gracia | Developer | |
| Atari | DeveloperPublisher | |
| Atari (Infogrames) | Publisher | |
| Atari (Infrogames) | Publisher | |
| Atari (NA) | Publisher | |
| Atari (Overseas) | Publisher | |
| Atari 2600 Land | Publisher | |
| Atari Corp. | Publisher | |
| Atari Corporation | DeveloperPublisher | |