While Atom RPG was fun, but generally quite rough around the edges, the Trudograd is a massive improvement ultimately in every way - better dialogs, graphics (the snow looks great!), map design, combat, QoL improvements, well everything - finally the post-soviet wastelands look like they should. Although it an expansion, it quite loosely connected to the previous title, so you may risk playing it first - I think it's much more new player friendly. If you are importing character from Atom RPG, I would suggest setting difficulty on expert (default)- on normal it was too easy. So take some warm clothes and see you in Trudograd :)