It works fine. Or, well, as fine as it can work.
The problem with other comps is probably that they have an outdated DX9. I've run into the same problem with my game, and every single time updating the DirectX has helped.
I played this for a while, but I'm kinda disappointed, it felt laggy and broken. I accidentally walked out of the level twice (once through a door, and after the Hum-Vee and the soldiers at the yard, I jumped over one of the fences...) Only 3 of all the soldiers in the level reacted to me, others just stood there while I shot them... And except for the first few rooms, the game ran at less than 17fps (although my crappy computer is a factor there)
I'll post a full crit tomorrow after playing more.
-Astek Games Developer-