Activate the following cheats by pressing the corresponding sequences of buttons at specified screen:

CHEAT FUNCTION - CHEAT CODE
Mission select - At the briefing screen, press UP, DOWN, LEFT, RIGHT, SELECT, START(2).
All ships available in all missions - At the main menu, press UP, DOWN, LEFT, RIGHT, SELECT, START, X
All ships in Skirmish and Multiplayer modes - At the skirmish screen, press UP, DOWN, LEFT, RIGHT, SELECT, START, SQUARE
Klingon campaign - At the main menu, press UP, DOWN, LEFT, RIGHT, SELECT, START, TRIANGLE
Extra crew upgrades - At the crew screen, press UP, DOWN, LEFT, RIGHT, SELECT, START, SELECT. You will get 5 promotion points that can be used at the crew screen.