Min. requirements are Vista, DX10 and Shader Model 3.0.
I hadn't bothered to read this until I had dl and launched it on xp, dx9.0c, no idea about which shader model but suspect < 3.0.
The game launched, and I was able to play through the 1st level (though my character was killed), albeit with a weird scrim-like pattern overlay that all but obscured the action. The 2nd level ctd'd. It does look pretty interesting, shall have to await my new system in 2048.