No PS1 game was over 4 discs and there were several 4 disc games released. As Rich statted Arc the Lad had more: Arc the Lad, Arc the Lad 2 (2 discs), Arc the Lad 3 (1 or two, cant remember) and then Arc the Lad Monster Arena. There was also a making of disc included. But that was a series of games and not a single title.