The game takes heavy inspiration from Ultimate Custom Night, a game in the Five Nights at Freddy's franchise that emphasized one of the series' prominent game-modes as its primary feature. It was released on February 1st, 2020, published by SmilerFurcifer on GameJolt.
Five Nights at Sonic's: Maniac Mania (also known as 'Maniac Mania Classic' and often abbreviated to 'MM') is a 'custom night' game, featuring (almost) all of the characters in the FNaS series, including infamous easters eggs that appeared throughout the games.