Guys please don't download this, you'll be banned from the MMP Discord server, thus banned from the actual game if it comes out(it's been confirmed by a moderator that they're putting in the efforts to make a game theme other than Mario so they can release it to the public safely). If you want to play this game safely, I'd recommend joining the MMP Discord server and hopefully get scouted by the staff to become a beta tester, it may sound stupid to do all this just to play a game, but it's worth a shot.
EDIT:I know I'm really late, but to the people who waited patiently without trying to get scouted(which is no longer a thing), a public demo of mario SINGLEverse is out on MMP.