Your screens are great. I really like the video you have of the train level. It doesn't show much, but I like what I see. The background is beautiful- all those trees and mountains in the background give you the feeling as if you're traveling through the Eastern European forests. The snow effect is excellent, and so it donates to the depressing atmosphere you're creating of World War 2 (that's when the game takes place, right?). And of course, the depressing, unpleasant music gives much to this atmosphere to develop.
If you want ideas for the game, how about a level where you are supposed to hijack an airplane? And then the next level the airplane gets hit by an enemy jet and you have to jump off in the middle of a forest? Also, a level on a ww2 destroyer sounds cool to me. Anyway, there are so many ideas that could be used in your project, and I wish you best of luck with it, since I see you're heading the right way.