Checking Steam, it's around 15k reviews so it's probably somewhere in the 450-750k range on that platform.
Normally I would feel comfortable saying this represents the bulk of all PC players but I honestly don't know how the Russian release was handled, whether it was launched there on some rival digital distribution platform or whether Russian players were using fiscal workarounds and vpns to get payments through on steam. Does anyone know what the situation is there?
In Russia and
CIS region overall PC version of Atomic Heart is officially an exclusive to VK Play.
VK Play is a PC games platform by VK (VK is a biggest Russian social network, like "Russian Facebook").
Atomic Heart was a very important project to VK Play, VK Play hugely promoted the game across Russian gaming sites, but reality is this store is just bad. There's nothing exciting, except for a few free-play games from Asia and local visual novels.
So I think some Russian players tried to use various "methods" in order to buy the game on Steam. How many people have followed this path, no one knows. Btw, Atomic Heart seems to be very popular in Russia. Its soundtrack is very successful, too.
In general, over the past year, many Russian gamers have adapted to buying games and paying for subscriptions through foreign accounts on different platforms. For example, PlayStation users are buying games from Turkish PS Store.
Don't know how I feel about these numbers. When you compare it to Outriders it pretty similar and that game never did turn a profit however the budget for Atomic Heart probably was significantly smaller so this could be deemed a success for the Publisher.
Do we know Outriders budget?
Forbes Russia experts estimate Atomic Heart' budget at $20-25 million (advertising costs not included).
https://www.forbes.ru/tekhnologii/485950-pramo-v-serdce-kak-suter-blokbaster-pro-robotov-v-sssr-atomic-heart-pokoraet-mir
Prior to the agreement with Focus Interactive, which became game's international publisher, Mundfish received investments from Tencent and other sources. In addition, Microsoft paid the studio to launch Atomic Heart in Xbox Game Pass. And VK Play paid to put the game in its store in Russia and CIS region.
(sorry for double post)