There is some video if you check out the official website (click any of the banners in my sig) and also there is some here
http://www.igromania.ru/games/?stalkerol its a russian site but here is how you can navigate it. Видеоролик means video clip, click on one of those links it takes you to a video description page then click on one of the folder items that are on the buttom part of the screen and you'll begin downloading. There are a total of 11 game play videos.