The Casebooks of Ace Harding includes Game Boy ports of Déjà Vu: A Nightmare Comes True!! (previously released on Game Boy) and Déjà Vu II: Lost in Las Vegas. Deja Vu is a port of a 1987 game that had been made for various systems. It's a classic detective story, with you waking up to a dead body with total amnesia - you don't know who you are, or how you got there, and you don't know who the corpse is, either. Déjà Vu II had never been released for Game Boy before, and was put in the same cart, selling for the price of one game.