Enter CMGTSMMGGTS as a password to activate the all weapons cheat.
Codes
DNCHN(shrinks enemys) - Dana's Cheat
GRGCHN - Greg Mode
LLTHCLRSFTHRNB - Purty Colors
CLLTHTNMTN - Quack Mode
RBNSMTH - Robin's Cheat
NSTHMNDNT - Show All Enemies
NTHGTHDGDCRTDTRK - Level Select,All Weapons, etc...
FDTHMGS - Show The Credits
THSSLKSCL - Spirit mode
DLKTDR - Pen and Ink mode
BLLTSRRFRND - Infinite ammo
FRTHSTHTTRLSCK - Infinite lives
THBST - Gallery mode
SNFFRR - Disco mode
CMGTSMMGGTS - All weapons
Dead Man Hunting
Turn on the Fly cheat and hold in R. The screen will go black.
Do not worry the screen will come back. But you'll notice you have no lives.If you turn off the flying cheat you'll die. So don't turn it off.
No enemies will notice you when you go back to the ground. Another thing you will notice is that there is no music. You won't have any weapons. You will be a zombie.
Fly Mode
To activate Fly Mode key LKMBRD into the password screen. Use L and R to go higher and lower.