Two special abilities at one time
Switch your ship's special ability to "Disruptor". Begin a new game, and hold [Special Ability]. While you are holding that key, click on the "Players" button and switch your special ability to "Shields". Select "OK". When the game is resumed, your ship will still be using Disruptor, but now you can use Shields at the same time. Note: If you die while doing this trick, you will have to redo it.
Return to life
After dying, press [Left] + [Right] + [Special Ability] + [Bullet] to immediately return to life.