I remember that in Steam version some achievements was broken, if I remeber correctly -something with game difficulty- if you complete game on Hard difficulty - anoyher levels of difficulty not counts! and this is so frustrting.
Yes, all achievements are real to get. If you don't know how to get one or another you may try to find help in different sources - there are alot of PC game manuals, one of them helped me to get one really sneaky achievement - Steam Achievements Guide
. You could try to find necessary info in it ;)
Many thanks for your help and yes - I do have problem with some achievements and hope, that now I will collect them all.