I tested the demo a few days ago..
It's a western(cowboys) FPS with decent graphics and bullet-time.
The scenario I tried had you playing an old preacher drunk killing everyone in town. It's really awesome, in one hand he holds a bible from
which you can manually recite!
He he, kill a few citizens and then condemn them to hell with a click on the mouse button. I think I heard at least ten different lines.
The voice acting is enjoyable as well, whining hicks from the 19th century.
There is some annoying box pushing in the demo and jumping feels a bit off. Other features are a kick function, kick down barrels and wooden fences!
At the end there's an old fashioned duel as well. Great fun for a demo.
The second scenario supposedly involves horse riding and whip swinging over ravines. Both scenarios are pretty short.
I used an A-64 3000, 1000 RAM and a Radeonx800 card. Didn't suffer any noticeable slowdown.
Possible download links:
http://www.fileplanet.com/165696/160000/fileinfo/Call-of-Juarez-Demohttp://www.3dgamers.com/dlselect/games/callofjuarez/cojspdemo_en_us_setup.exe.html