The Brutal Legacy of Ghouls n Ghosts
This legendary 1988 platformer is notorious for its crushing difficulty. Players are forced to beat the entire game twice in a row just to see the true ending.
Capcom designed this sequel to challenge even the most skilled arcade gamers of the late eighties. After reaching the final boss, the game resets to the beginning and demands you play through again with a special weapon to unlock the final scene. This punishing requirement became a hallmark of the series' reputation. It remains a classic example of how developers pushed players to master every inch of a game.
Source: Ghouls 'n Ghosts