Mario Multiverse is a custom-built 2D sandbox game designed to allow player-created levels using assets, physics, and themes spanning the entire history of the Mario franchise. It goes far beyond standard level creators by including:

Thanks for testing, and have fun dimension-hopping! 🌌🍄

For those who do manage to get their hands on a legitimate client build, the scope of Mario Multiverse goes lightyears beyond an ordinary level editor:

Official community channels (such as the developer's official YouTube channel or the official Mario Multiverse Discord server) are the only secure routes for access. Developers have explicitly warned that using leaked versions of the game will result in an from ever becoming a beta tester, not to mention the security risks of downloading executable files from unverified third-party websites.