Vostok went free-to-play online with Survarium in order to secure funding 

Vostok Games project manager Ruslan Didenko has said developing Survarium as a free-to-play, multiplayer-focused title was a "tough decision to make."

Speaking with Gamasutra, Didenko said the team went went this route in order to secure funding for the game.

"It was a tough decision to make," Didenko told Gamasutra. "After the shutdown of GSC, our team had a choice: whether to scatter around other companies or stick together and try to attract funding to keep the development going."

While sorting funding from local venture capitalists, the team realized it would be next to impossible to acquire the money it would take to develop a large,single-player games along the same lines as S.T.A.L.K.E.R.

"Those games take a long time, cost a lot, and leave a lot of revenue in the pockets of publishers," said Didenko. "What we realized is that while we had been preoccupied with delivering single-player titles one by one, the world changed, and we have to change too. Therefore, we decided to take a dramatic step and switch to online."

Vostok announced Survarium as a spiritual successor to S.T.A.L.K.E.R. in April, and the game is slated for a 2013 release.