Rengoku: Tower Of Purgatory Codes -

Alternate ending sequence:
Successfully complete the game two times to view an ending sequence that features a bonus FMV sequence.

Gallery pictures:
Complete the following tasks to unlock the corresponding picture in the gallery.

A.D.A.M: Save the game once. 
Deucalion-A: Successfully complete the game twice. 
Deucalion-B: Successfully complete the game twice. 
Gryphus: Defeat Gryphus in the level 8 Boss fight in the Tower. 
Lycaon: Defeat Lycaon in the Tower. 
Mars: Defeat Mars in the Tower. 
Statius: Defeat Statius in the level 7 Boss fight in the Tower. 
Type01: Save the game once. 
Alkmaion: Defeat Alkmaion in the level 6 Boss fight in the Tower. 
Briareos: Defeat Briareos in the level 4 Boss fight in the Tower. 
Minos: Defeat Minos in the level 3 Boss fight in the Tower. 
Sphinx: Defeat Sphinx in the level 5 Boss fight in the Tower.