# 100 Serum Vials in Killer 8 mode

At the "Press Start" screen for Killer 8 mode, press Down, R1, Up, L1, Square, Triangle, Circle(2). If you entered the code correctly, you will hear the healing sound. You will get the vials when you start Target: Angel. Repeat the level over with the code enabled to get another 100 vials.
# Play as Young Harman

Successfully complete the game on the normal or hard difficulty setting to unlock Young Harman.
# Killer 8 mode

Successfully complete the game on the normal or hard difficulty setting to unlock the Killer 8 difficulty setting.
# Hopper 7 mode

Successfully complete the game on the Killer 8 difficulty setting to unlock the Hopper 7 difficulty setting.
# Alternate ending sequence

Successfully complete the game on the Killer 8 difficulty setting to view an alternate ending sequence.