Targets 1 - 6 represent areas of the enemy ship, and the associated 1 - 6 lights represent the shields protecting those areas.
Hit the target to take down the associated shield. Once the shield is down, hit the exposed target to do damage.
Your enemy is monitoring his displays for his power level and status of his shields. He can regenerate his shields by collecting crystals.
Crystals are gathered by various tasks on the playfield: the spinner and pop bumpers are particularly rewarding. Your crystal count is shown on the playfield 1-10 vertical light scale. Gather ten crystals to automatically regenerate a shield.
Lock your torpedoes in any of the three tubes. Hit the top center target to release locked-in torpedoes for multi-torpedo attack.
Stray torpedoes can damage your own ship: side drains give you some damage, but you'll suffer even more from a center drain.
You have unlimited torpedoes, but not unlimited power. Each hit drains your power, and there's no restoring it.
When your power is critical, the alarm is sounded, and the next hit you take will destroy you.
Quick, even after the death blow, you may have a few seconds to launch some final torpedoes to take your enemy down with you.