Nintendo’s notoriously single-player boxing game SuperPunch-Out!! was released to nearly universal praise 28 years ago. One issue for some reviewers, though, was the game’s lack of a two player mode. Through numerous re-releases on consoles, there has never been a way to play the game with a friend—except there actually was the whole time. This week, UnlistedCheats on Twitter revealed a hidden multiplayer mode in the game, accessible with cheat codes, that allows it to be played with two people for the first time.