I have regional restrictions,but why ? I am from Ukraine

I know that people from Russia can't play, but i am from Ukraine and i have the regional restrictions, please help me

You play through steam...thats why.
play the standalone and there are no such restrictions.

i didn't know this game wasn't allowed to russian gamer using steam (i hate steam: selling virtual stuff and taking 30% fee whatever happen) ...how does it comes?

EDIT:

ok! i saw partial explanation: the currencies exchange rates.
It to also apply to south-east asia and south america (all full of non-aligned countries)

Valve seems to follow the "free world" rules ;o

As far as i know it's steam being greedy, because they get a cut of anything bought in game through steam and the exchange rates meaning less moey for them.

Yeah, i've read a little, and that's pretty much the best explanation: greed