My partner’s been playing Fields of Mistria and the art direction looks like it’s Game Boy Advanced era which is kinda neat.
She’s always complaining about forgetting to put the chickens away xD
When it was free on steam it was a much more generic ww2 game and I believe the factions didn’t even have the fictional names they have now.
Now the devs have made a point to say it is not a simulator for any of the world wars though inspiration has been drawn from an amalgamation of 20th century warfare.
It’s completely fictional but the other reply is accurate in that it’s more WWI or interwar period themed.
Their newest game is going to be on a custom engine. As for the games still being updated or about to release I think they said would be very expensive to rebuild in a new engine at this point.