Here are some cheats and tips for the game Killer7.
Killer 8: 100 Serum Vials:
Press Down, R, Up, L, Y, B, X, A(2), at the the “Press Start” screen.
The healing sound will confirm correct code entry. You will get the
vials when you start Target: Angel. Repeat the level over with the
code enabled to get another 100 vials.