Developer: HAL Laboratory
Released: 2001, Nintendo GameCube
Super Smash Bros. Melee was the anticipated follow-up to Nintendo's crossover beat-em-up sidescroller game for the Nintendo 64. It became an unexpected big hit thanks to its prominence in competitive gaming events, which is still used to this day.
The game was released rather early in the console's lifespan, resulting in a rather large chunk of unused and overlooked content such as an extensive debug menu, unused test stages and modes, graphics hidden in various places and even some regional changes!