The fun thing about the “use the force” quote is that it was a clue. If you could channel your inner Jedi, and the only shot you fired while in the trench was

The fun thing about the “use the force” quote is that it was a clue. If you could channel your inner Jedi, and the only shot you fired while in the trench was the one into the exhaust port, you were granted a pretty decent bonus (especially in the higher numbered waves).