Trudograd is to be described as a stand-alone expansion; yet, it is a separate game.
While ATOM RPG is
not required to play Trudograd, one
can transfer data from a previously-completed ATOM RPG save file which enhances playing experience within Trudograd.
Refer to the following RPG Codex post, written by Atomboy (member of Atom Team):
https://rpgcodex.net/forums/threads/atom-rpg-trudograd-released.140112/#post-7501829 You start at 15, or if you transfer save file you get the level you finished Atom on. The game reacts to your distinctions made in the first game, you begin hearing rumors about the cities you destroyed or saved or left to stagnate, you get to hear about people featured in ATOM's minor quests, and of course you either get or not get Hexogen depending on whether he survived in your save. Other than flavor text and stats - no changes between transfer and new game. Plus with a new guy you get to re-make past choices anyway in the opening vigniette.
Currently, a bundle which includes ATOM RPG and Trudograd does
not exist (at least, not on GOG).
