Control your ship and destroy enemies. The ship is destroyed when it is hit by a bullet. The body of the enemy has no collision damage.
You can catch the enemy's broken piece. Pieces are stuck to your ship and counterattack to enemies. You can also earn the bonus score by keeping many pieces stuck. Stuck pieces are destroyed when they touch a enemy's bullet.
While holding a slow key, the ship becomes slow and the ship direction is fixed. Stuck pieces are pulled in and you can prevent a crash of them, but the bonus score reduces to one fifth. Enemy's pieces are not stuck while holding this key.