Mission: Impossible cheats and cheat codes for Nintendo 64

Go to the mission selection screen and press the following button 
combinations. Note : If the codes are accepted, you should hear 
"Ah, that's better" phrase.

Enable big feet mode: C-Down, R, Z, C-Right, C-Left.
Enable big head mode: C-Down, R, C-Up, L, C-Left.
Enable giant head mode: C-Down, L, C-Up, C-Right, L.
Enable kid mode: C-Down, C-Up, R, L, Z.
Enable turbo mode: C-Up, Z, C-Up, Z, C-Up.
Get 7.65 silencer gun: C-Up, L, C-Right, C-Left, C-Up
Get 9mm high-power gun: R, L, C-Down, C-Up, C-Up
Get Mini-rocket launcher: R, L, C-Left, C-Right, C-Down
Get Uzi: C-Right, C-Left, C-Right, C-Down, R 
Invincibility: R, Z, C-Down, R, C-Down. 
Unlimited ammo: C-Up, Z, C-Left, Z, L.

Easy mode - Turbo mode with double health and less damage:
Continuously tap C-Up, Z.

Bonus stage:
Finish the game and watch the entire credits. When the Infogrames logo 
disappears, the development team will appear on the Embassy stage. 
Talk with all the people here, then Ethan and Candace will 
enter the room.