GSC Game World has said S.T.A.L.K.E.R. struggled across North America because no one cared about a silly old nuclear disaster in Russia.
Developer mouth Oleg Yavorsky was speaking exclusively to Eurogamer, and said finding a topic to interest distant cultures was tricky.
"We've never had problems with getting Europeans to understand our games, and we have had problems with North America and Asia," said Yavorsky. "We've always tried to find local topics that will be relevant and interesting to people all over the world.
"Also, we've always created hardcore games, and the mass-market audience is now pretty much casual. Big companies always want you to make your game as easy as possible, so that any really non-intellectual person can play it. They want all sorts of tutorials to guide the player through, and this is something we've always been very resistant to.
"But then, everything, even up to the colour spectrum and how bright your game is, can be an issue. It seems that to appeal to North America you need really flashy, bright games, and you can see that every Eastern European game is very dark," added Yavorsky.
However, S.T.A.L.K.E.R. did review universally well, and sits at a very favourable 82 per cent on Metacritic.
Head over to our full interview with Oleg Yavorsky to hear what he had to say about the six years it took to make the game and why the Russian and Eastern European PC market was so appealing.
Alternatively, head to our preview of S.T.A.L.K.E.R. prequel Clear Sky to see how it's shaping up.