S.T.A.L.K.E.R.: Clear Sky (PC) will arrive in North American retailers on September 15, publisher Deep Silver announced today.

The GSC Game World-developed shooter prequel was previously expected to hit September 5, but suffered a delay due to a North American manufacturing problem that reportedly saw the game head to stores without the CD key codes required for play.

Curiously, a cloud of uncertainty hangs over the game's once-simultaneous release on Valve's digital distribution network Steam.

Though Valve has announced that S.T.A.L.K.E.R.: Clear Sky will be downloadable on September 15, Deep Silver today stated digital download release date "has not yet been determined."

The North American release of GSC Game World's S.T.A.L.K.E.R.: Clear Sky (PC) has been delayed "a few days" past the promised September 5 date, a representative from publisher Deep Silver confirmed with Shacknews today.

The slip stems from a manufacturing issue specific to the North American edition, with Deep Silver forced to recall all copies that have already shipped to stores. The issue is apparently a printing error that saw the game distributed without CD keys, according to Bluesnews.

This delay will "probably" push back the shooter prequel's impending release on Valve's digital distribution platform Steam, though direct confirmation has yet to arrive.

The game's European release on September 5 is not affected.

A new release date for North America is not yet available, though several online retailers have the title tentatively slated for September 15.

As the worldwide September 5 release of S.T.A.L.K.E.R.: Clear Sky (PC) draws near, developer GSC Game World has provided new screenshots from the shooter prequel.

The worldwide release of GSC Game World's post-apocalyptic survival shooter prequel S.T.A.L.K.E.R.: Clear Sky (PC) has been pushed from August 29 to September 5, publisher Deep Silver announced today.

No reason was provided for the brief delay, which accompanied news that the game has gone gold and is now in the manufacturing process.

A new trailer from GSC Game World's S.T.A.L.K.E.R.: Clear Sky (PC) has arrived by way of publisher Deep Silver, showcasing the new technology, effects and environments contained in the upcoming shooter prequel.

Clear Sky is due out August 29. For more information, check out the recently released details of the game provided by the publisher.

Developer GSC Game World has released new details from its upcoming survival FPS S.T.A.L.K.E.R.: Clear Sky (PC), due out August 29 from publisher Deep Silver.

A prequel to the 2007 shooter S.T.A.L.K.E.R.: Shadow of Chernobyl (PC), Clear Sky is set just one year before its predecessor. Players take up the role of Scar, a mercenary caught up between warring factions competing for power and territory.

The publisher touts the game as delivering a "realistic simulation" of the S.T.A.L.K.E.R. world in which mutants hunt on their own and enemy factions fight eachother, leaving the choice to the player as to which side to join.

From the publisher:

War of factions
In S.T.A.L.K.E.R. Clear Sky, the player assumes the role of Scar, a mercenary s.t.a.l.k.e.r. In a unique mixture of first-person shooter and complex role- playing game, Scar fights for survival within the Zone and its hostile sectors. The new Zone territories are explored by... Read more

Former European-only publisher Deep Silver has announced that it will be publishing the North American edition of S.T.A.L.K.E.R.: Clear Sky (PC).

Though developer GSC Game World revealed long ago that its survival FPS prequel would hit retailers and Steam on August 29, no North American publisher was listed at the time.

Owned by larger publisher Koch Media, Deep Silver expanded its operations to include North American publishing less than a week ago.

New at FileShack is a trailer from developer GSC Game World showing off some of the DirectX 10 effects in the upcoming survival FPS-RPG S.T.A.L.K.E.R.: Clear Sky (PC).

Included in the demonstration are glimpses of god rays, soft water, volumetric fire, dynamic wet surfaces, water splashes, and more.

Get the Flash Player to see this player.

A prequel to the original S.T.A.L.K.E.R. (PC), Clear Sky will be available through traditional retail channels and as a Steam-exclusive digital download beginning August 29.

GSC Game World's upcoming survival FPS S.T.A.L.K.E.R.: Clear Sky (PC) will arrive worldwide on August 29, the company announced today.

Set before the original S.T.A.L.K.E.R., the prequel provides insight into the events that led to the atmospheric first-person shooter. The title will be available through both traditional retail channels and as a Steam-exclusive digital download.

"Our intention to deliver the game simultaneously worldwide is both a challenge and big responsibility to the many fans of the game around the globe," said GSC World Publishing CEO Sergiy Grygorovych. "We are looking forward to achieve this ambitious goal in August."

GSC Gameworld has unveiled a new set of screenshots for its upcoming standalone prequel S.T.A.L.K.E.R.: Clear Sky (PC).

The new screens showcase the dark landscapes and vistas of the upcoming prequel, which is said to flesh out the story of one of the main characters from the original title.

S.T.A.L.K.E.R.: Clear Sky will be available later this year, both in traditional retail channels and via exclusive digital download on Steam.

Valve announced today that GSC Game World's S.T.A.L.K.E.R.: Clear Sky (PC) will be made available as a digital download exclusively on Steam, and unveiled a handful of new screenshots of the upcoming standalone prequel.

S.T.A.L.K.E.R.: Clear Sky is tentatively scheduled for simultaneous retail and digital release later this year.

Get the Flash Player to see this player.

Computer & Video Games has a S.T.A.L.K.E.R. Clear Sky Q&A up, asking Anton Bolshakov about the game. Topics include storyline, PC game development, DirectX10 and new gameplay features.

PCGH Extreme has a S.T.A.L.K.E.R. Clear Sky Q&A posted, mostly asking programmer Igor Lobanchikov about engine features.

GSC Game World has released the first S.T.A.L.K.E.R.: Clear Sky trailer, showing gameplay footage from the next S.T.A.L.K.E.R. installment which was revealed last month.

Get the Flash Player to see this player.

According to Computer & Video Games, GSC Game World is working on releasing the next S.T.A.L.K.E.R. chapter next year.

Titled S.T.A.L.K.E.R. Clear Sky, the game is said to be a prequel to S.T.A.L.K.E.R.: Shadow of Chernobyl, fleshing out the story of one of the main characters of the first game. The game world will consist of a mix of familiar and new territory, with more anomalies and vastly different landscapes.

On the technical side of things, look for interface and PDA tweaks, along with overhauled AI.

Update: We now have screenshots.