@Sivan
Yes, using 2d art is good way to create a nice backgrounds. I do not have some big problems in levels where my camera pan/tilt/z is locked like here:

But in levels where camera is much more dynamic, i need use a 3d art style and i never satisfated with results.
@Kartoffel thanks for info, i was almost sure that it was a shader Now i know i just need play more with fog and my models.
@FEL
About "swich engine virus" which circulating around here, i'll be immune to it until i can achieve my goals with Acknex. At this moment Acknex in current state is more than enough for the type of games for which i'm interested. I'm thinking that for the time i would have spent on learning a new engine, it is better to make the 2-3 games and publish it.
Why pay penalties for UE, when we know how to ride the dead horse