Anybody on this site should immediately purchase ALL of Interplay's back catalogue. They are incredible, and this is one of their finest.
Great voice acting, an excellent plot, plus a dynamic campaign that gives more replayability than you'll ever want is blended with beautiful graphics and completely original gameplay. It may be something of an aquired taste, being very tough and more than a little cerebral at times, but for $5.99, even if you hate it it will be good value.