All cheats available:
To get all the cheats you pause the game and then hold the L trigger Down and press X, Up, Down, X, A, B, Right, Left, Down

A nice strategy:
A nice strategy, when you are protecting something is to use your after burners. To do this hold the right trigger down then press the top button near the trigger. Afterburners are very useful. Fx. mission eight is to protect the Reliant, because it need repairs and you are to guard it. This mission is very difficult without after burners because there are three torpedo bombers that come from different directions. You'll need to take them out the torpedoes before they get to the Reliant. Afterburners are also useful if you need to catch up to something or run away