Initially, my friends hesitated to download the game until I showed them a fragmovie of Rexuiz. Besides being entirely free, it runs on any computer (just like DOOM) and any operating system. I've never seen anything like it - top-notch optimization, quality graphics, and plenty of adrenaline. This, in my opinion, sets a new standard for online games. I forgot to mention, unlike most triple-A games, this one is free.