Pull the rocks and make your way through dangerous places

Gravity Gunner is a mouse-and-keyboard controlled horizontal shmup with one level, inspired mechanically by Half-Life 2. You are piloting a space fighter with no weapons, save for the Gravity Gun, a device which pulls rocks towards your ship. Use it to navigate the treacherous interstellar terrain ahead. There's one small kink, though - once you start pulling a rock toward you, you can't stop pulling it toward you unless you select another rock. This means you'll have to dodge most of the things you drag out! Be nimble, pilot. How long can you survive this deadly maze?