The secret fighters in this game are unlocked the longer the arcade machine has been running since initial boot-up. Newer single-PCB versions of the game eliminate the time-based unlocking mechanic and make all the fighters available from the start. Unlockable fighters include the Miclus and Fairy (both collectible score items in the "Raiden" and "Raiden Fighters" series). Introduced in this game are the second-player colored variation of the Raiden mk-II and Judge Spear, dubbed the Raiden mk-IIβ and Blue Javelin respectively, each with different weaponry and attributes than their counterparts.