Switch to terrorist hunt map:
Once online, go to mission then return to team survival. Choose Hotel or Nuclear 
Facility. Instead of being the original map for it, it will be the Terrorist Hunt map. 
The terrorists are still in the game -- be careful. Also, it might have "0" next to the 
stars for your connection and it will not rise. This also makes it slightly more 
extreme to see if you and your opponents can work together, then afterwards kill 
each other.

Laser trails:
Press Up, Down, Up, Down, click Right Analog-stick(2) during game play. Rainbow 
weapons will shoot red laser trails and opposing force weapons will shoot blue 
laser trails.

God mode:
Press Up(2), Down(2), Left, Right, Left, Right, B, A during game play. The 
message "God Activated" will appear to confirm correct code entry. Note: This only 
seems to effect you, and not your team or hostages.

Credits level:
Click Left Analog-stick(2), click Right Analog-stick(2), press X, Y, B, A, B, A at the 
main menu.