I've been reading the previous authors' comments... and couldn't but help laughing.
This movie was never intended to be serious. It is nothing more than a parody on all the previously shot Russian "gang" movies ("Bumer," "Brat," "Brigada," etc.) - same as the "Scary Movies" have always been made as parodies on everything else that the Hollywood had churned out around the same time. I am amazed that nobody seemed to catch that. And, oh yes, this is why the 50 liters of blood were absolutely necessary! Given this, the movie was fun. But it does NOT portray any reality. The kid-like looking criminals (especially the smaller one) do not even closely resemble the real "bratva," and 15 head shots in one day have never been a norm in Russia, not even in the early 90's. The mafia boss (Nikita Mikhalkov) in his maroon jacket is a perfect portrayal of the Russian anecdote character of "noviy russkiy," but you have to understand that it is not much more than a folklore character. Hardly any real "new russians" ever looked like that in reality.
Makovetskiy ("Koron") and his two gang-members (especially the dumb one) look absolutely nothing like a real hit-man gang. Sukachyov ("Brain") is completely overdoing his role of a "vor v zakone," so that, once again, the viewer does not forget that it is all a parody.
The "Doctor"'s drug-lab set-up in the beginning of the movie is a replica of a typical comic book-style "bad scientist" set-up.
I could go on... but I don't see the need. Just take this movie for what it is... and enjoy!