OpenAI Universe is described as 'Part of the OpenAI project, Universe is a platform for measuring and training an AI through a supply of games, websites and other applications'. There are four alternatives to OpenAI Universe for Linux, Mac, Windows and Online / Web-based. The best alternative is Bomberland by Coder One, which is free. Other great apps like OpenAI Universe are ELF (Free, Open Source), SerpentAI (Free, Open Source) and OpenNERO (Free, Open Source).
Bomberland is an online 1v1 AI sandbox inspired by the classic console game, Bomberman. Players program intelligent agents using strategies from tree search to deep reinforcement learning and compete against teams across the globe.
Serpent.AI is a simple yet powerful, novel framework to assist developers in the creation of game agents. Turn ANY video game you own into a sandbox environment ripe for experimentation, all with familiar Python code.