Type these at the password screen:

Password - Effect

UANWIJPA - Level 5 Stage 1
UAGWIJPE - Level 5 Stage 2
UAGWGQPA - Level 5 Stage 3
MUVWLGEC - Level 5 Stage 4
UKCLPMHT - Level 5 Stage 5
UAGWGIPE - Level 5 Stage 6
UAGWGSPA - Level 5 Stage 7
UANWIJPZ - Level 5 Stage 8