While playing the game at any time type in KIRK to activate god mode. While your power does go down it will automatically be refilled. You can tell this code is active by a little pointing hand above the meter.

While playing the game at any time type in SPOCK, it lets you skip the current level of the game to the next phase of Ensign Sovok's assignment

While playing the game at any time type in SCOTTY. This code gives you all keys and passcards (Very helpful later on when you have to go around looking for them)

While playing the game at any time type in BONES. This code gives you one hypospray (But, if you have the KIRK mode on, hyposprays are useless)