Radiant Silvergun Hidden images: Insert the game disc into a PC compatible CD-ROM drive and look in the "Furoku " directory for several bitmap graphic image files. Level select: Successfully complete the game one time. Select game speed: Accumulate more than three hours of game play. View attack range: Accumulate more than twelve hours of game play. Change plane speed: Accumulate more than forty-eight hours of game play. More credits: An additional credit is available for each hour of game play that is accumulated.