What are RetroAchievements?
RetroAchievements.org is a zero profit community who collaborate and compete to earn custom-made achievements in classic games through emulation. Achievements are made by and for the community. We provide various custom-built emulators for you to use which will detect when you have completed various challenges. Once logged in, the emulators will post the achievements you've completed back to the site, so you can check and compare your progress to your friends. -https://docs.retroachievements.org/FAQ/#what-is-retroachievementsorg