Power up all ships:
At the Main Menu, press Right, L1, Up, Up, Down, Right, R2, L2, R2, Down, Up, Down. You'll hear an explosion to confirm. Now start a game, then quit. This should power up 4 ships and open up Sector 5.
Wraith ship:
First enter the "Power up ships" code above. Now at the Main Menu, press Left, Right, L1, Left, Right, L1, R2, R2, L2, Left, Right, Up. You'll hear an explosion to confirm. Now start a game, then quit. The Wraith ship and Sector 8 will be unlocked.
Extra levels:
Note: This code won't work with the "Power up ships" or "Wraith ship" codes. At the Main Menu, press L1, Left, L2, Down, Select, Left, Down, R2, R2, R2, Select, Up. You'll hear an explosion to confirm. This should open up 4 secret missions.
Wierd planets:
Note: This code won't work with the "Power up ships" or "Wraith ship" codes. A the Main Menu, press Down, Up, L1, Right, L1, Up, Right, Select, Right, R2, L1, L2. You'll hear an explosion to confirm. The planets will now either have faces or objects in their place.