In Galaga you have these enemy bugs that take two hits to destroy.

They're the only ones in the game with a tertiary attack, instead of shooting or running into you, they can fire a tractor beam.

If they hit you with the beam, they'll capture your ship, and then attack you with it, it's dirty pool.

But!

If you can shoot down the enemy bug without damaging your ship, then you get yours back, and it's grafted onto your ship, doubling your firepower.

The downside is that now you're a much bigger target, and have two of your ships in play at the same time.

Is the tradeoff worth it? You'll have to decide that.

Just make sure that you don't let your last ship get tractored. That's a pretty lame way to lose the game.