Reset Mission Time
Press ALT+SHIFT+V and access your inventory. You will have the viewmaster. Use it an the screen will flash blue, your ranger will jump and the time will reset giving you the time that the mission started with.

Training Mode
To enter training mode go to any level. When the level starts press the "t" key. This code allows you to travel the level without being timed.

Invincibility unlimited time
During The game, if you press ALT+shift+V, after you hear the sound of a
gun loading go to your Inventory and you find a thing called view master
click on it your screen will go blue for a couple of seconds after you have
done all this you should have god mode and every time your time limit gets
low click on viewmaster and your time will reset

All Missions
To access all the missions in SpecOps, move the savedata.txt file out
of the SpecOps directory.