Silent Scope cheats and cheat codes for Dreamcast

Go to the mode selection screen and enter the following button 
combinations. Note: If the codes are accepted, you should hear 
a sound of a gun.

First person view: Press Up, Up, Up, Up, Down, Down, Down, Down.
Turbo mode: Press Down, Y, Up, X, Y, Down, Right, Down, Right, X, Y. 
Love mode: Press Left, Right, Right, X, Y. 
Night mode: Press Up, Right, Down, Left, Up, X, Y.
Disable crosshair: Press Right, Right, Right, X.
Disable scope: Press Right, Down, Right, X, Right, Down, Right, X.
Disable enemy cursor: Press Right, Right, Right, Right, Left, Down, Up, Right.


Secret mode
Press Right, Down, Right, X, Up, X, X, Y, Down, Right, Down, 
Right, X, Y.

Reveresed levels
Press Left, Left, Right, X, Down, Down, Up, Y, Up, Right, Down, Up, 
Left, Down, X. 

Exchange a half of life for 5 seconds
Pause the game in arcade mode and press Up, Up, Down, Down, Left, Right,
Left, Right, A, B.

Exchange 5 seconds for half of life
Pause the game in arcade mode and press B, A, Right, Left, Right,
Left, Down, Down, Up, Up.

Unlock 100 challenge mode
Finish all 9 outdoor shooting range challenges

Extra options
Finish the game on any difficulty mode

Unlock unlimited credits and +30 in the time limit section. 
Finish the game at least 3 times on any difficulty mode