Canyon

Maneuver between the twisted walls of the canyons, trying to avoid crashing into them or the islands in your path, and also avoid the Beamers, Bombers, Missile Boats and Proximity Mines. Just when you think it is safe to relax... you have to pass through the Gates of Fire; and then, battle-scarred and thinking yourself victorious, you encounter the imperial flagship.

The game is essentially similar to River Raid, except you're in space, and you go down the screen instead of up.