Holy smoke, that was awesome!
And man, it came out of nowhere!
Plus, I really enjoyed the fact it's Russian through and through; none of that hokey claptrap where characters begin by speaking in Russian, then after a scene or two begin speaking English. (Man, that drives me bonkers.)
Anyway, if you dig sci-fi creature features (like Alien, The Thing, or even The X-Files), Sputnik's calling your name.