For those of your looking for (or complaining about) a new "breakthrough" in a FPS game, this isn't it. However, in my opinion, it is fun. The graphics and animations are better than SS and everything just looks a little crisper to me. And it ran just fine on my machine (1.2/ Radeon 9700 Pro) Yes, it is the bigger brother of SS. That said, if you liked/loved SS then you will like this also (unless you are a SS fanboy and hate the fact that it is blatant rip of your game).
Plus, lets not forget, it only costs $19.99 (Amazon)
Anyhow, just my 2 cents. I will be picking it up.