Halo for the Atari 2600
atariage.com
atariage.com
(Are the controls listed anywhere?)
Z key => shoot
Magnum Pistol is located upward from the starting position.
It's the only 2600 game that I know that has physics and that's why I think it's the best.
I really want to see a youtube video of this.
Also as part of a class dedicated to the Atari 2600 I made these games: http://nirmalpatel.com/hacks/atari.html
Let me know why you think.