Speaking of the controls in Gun, first person shooter fans should be happy. The game controls almost exactly like a standard issue first person shooter. The two analog sticks control your movement, R1 shoots, R2 activates the Quick Draw mode, L2 crouches, pressing left or right on the d-pad allows you to lean in either direction, and pressing up on the d-pad will give your character a quick shot of whiskey to replenish some health.
After acquiring our horse, we headed for Dodge City. Keep in mind that this is the old west, which means that just about anything goes. So if you lose your horse, you can simply steal another one, but stealing a man's horse is like committing grand theft auto (grand theft horse?), and it could get you into trouble. In fact, if you just randomly start shooting people, the town's patience meter will build until they start forming posses to take you out. There are random fights that you can get involved in, but don't take things too far, or you'll upset the townspeople. As long as you keep this in mind while you're in Dodge City and other various towns, you'll be okay.
Full Preview: http://www.gamedaily.com/playstation2/preview/?id=121&type=1&game_id=4478
There's a new trailer as well, but it's still uploading to the server. Please link if you find it before it's been posted at GD.
EDIT: New trailer - http://www.gamedaily.com/gp/dlexe.asp?packageid=0078700390&gameid=4478