How many games can claim to still have a dedicated following, 10 years after their release? That still have fans conjuring up new mods to alter and add to the game? S.T.A.L.K.E.R.: Shadow of Chernobyl is pretty much the definition of a video game cult classic. This strange Ukrainian survival shooter is for some the best the genre has ever seen. But its audience wasn't spurred into existence upon the game's release. Fans had followed the development of S.T.A.L.K.E.R. for years before it eventually came out in 2007. In that time they saw various versions of it, each containing numerous areas and mutants that never made it into the final game.

Shadow of Chernobyl launched to a generally positive reception. Whilst riddled with bugs and lacking in polish, the game's ambition and exemplary atmosphere shone through. It attracted a most passionate fanbase and managed two sequels in the form of Clear Sky and Call of Pripyat. Sadly though, in 2011 developer GSC Game World was dissolved and there have been no further entries in the series since.

The mod scene for S.T.A.L.K.E.R. however, only continues to grow. There are numerous gargantuan efforts that rework almost every aspect of the games and add in numerous new features. While they all share a love of S.T.A.L.K.E.R., what they want from it varies considerably. Some want a harsher, more realistic experience like that offered by the lauded Misery mod. Some just want a more interesting weather simulation, with the excellent Atmosfear mod reworking the game's ambience into something more varied.

Yet for a few fans, their minds remained curious about what might have been, about the game they had seen over the years but were never able to play. It's the kind of thing that captures the imagination but seldom becomes more than that. But for dedicated fans Dezowave, what might have been became a challenge. This team of modders began working on a massive project, a standalone mod that would recreate the version of Shadow of Chernobyl that continued to draw their curiosity.

They called it Lost Alpha.

The mysterious zone continues to fascinate fans.

"After the game came out, we joined forums and we started to discuss the cut-content," Zoltan Munkacsi, Dezowave's Hungarian chief, tells us.

"We were working on Priboi Story [another S.T.A.L.K.E.R. mod] back in 2007 / 2008, and meanwhile I was doing some research with a mate, who later joined us [Loxotron was his nickname]. We had our own connections to GSC, mailed them, and had them on icq [chat application].

"We had lots of concepts which we created even before Lost Alpha, mostly for the second episode of Priboi Story, but our team could not work on two different projects at the same time, so we decided to go for the new, fresh stuff. That's how Lost Alpha was born."

Recreating a game that never officially existed was no small feat. Dezowave had to use numerous resources for reference.

"We had lots of screens and videos," Munkacsi explains. "We started to remodel the areas using those collected images. It was a long process. Our Dead City became three times bigger than the cut variant, and this is true for all our remade levels. We simply used our imagination, as we did not know the interiors of those buildings."

Dezowave ended up going the extra mile though. "We modelled everything on our own until 2010, when we got access to GSC's server backups, which contained all their objects from 2001 to 2009, and lots of goodies," Munkacsi reveals.

"We were lucky because of that."

You can take a look at Dezowave's level building here.

Even stranger monsters were cut from the game.

It wasn't just old areas that were brought back to life either. Weapons were reused using old textures on final models. Most of the mutants were also in-game - only the little dwarf and the yellow "karlito" wasn't. Dezowave found the little dwarf in GSC's backups in 2010, and recreated animations to make it work in Lost Alpha. The yellow "karlito", aka the first version of "burer", was made from scratch.

"It looks almost 1:1 the same as the old version," Munkacsi says, "which probably only existed for a short period of time, since its original model was overwritten with the later variant of burer."

Of course being a restoration mod didn't prevent Lost Alpha from having to make concessions to time and resources. Dezowave had to cut the skills module from the PDA and two levels, which weren't finished. But both of the cut maps are no great loss - they referenced unreleased GSC test maps, which were only prototypes.

"We found these draft terrain textures and models so we started to rebuild them. Hopefully they will reappear again in the near future," Munkacsi says.

An extra ambition from Dezowave was to expand the story content of Shadow of Chernobyl too, but sadly this never made it to fruition.

"We wanted to show how Strelok met his mates (Ghost, Fang, Guide) and show his first encounter in the north. It was a nice plan, but we did not have enough help to bring it to life, so we had to drop it."

Lost Alpha is a significant graphical overhaul, too.

Lost Alpha sounds like less of a mod and more of a fully-fledged game (Dezowave's group page shows just how many people were involved in development) - and at one point GSC Game World considered making it an official, premium add-on to Shadow of Chernobyl. In this world of cease and desist orders, this was a tremendous rarity. However, disaster struck. In 2014, some of Lost Alpha's testers leaked an in-progress build to the public - a build that suffered from a raft of game-breaking bugs. Not only did this leave Dezowave's dream of an official release in tatters, the developers faced a wave of negativity from those who failed to understand they were never meant to play this version of the mod. Team members dropped out. It seemed like the writing was on the wall for Lost Alpha.

Dezowave, determined to continue the work, moved forward anyway, frantically building patches to get Lost Alpha's leaked build in a playable state. It was at this point that the Developer's Cut was born.

"While we were working on the fourth patch - namely 1.3004 - it became more and more clear we needed to release the Developer's Cut, because the content we were planning was simply bigger than a patch," Munkacsi says.

The new label would quell the tide of negativity associated with the game and assure fans that this would be the complete and polished version of the game. It would also let Dezowave give Lost Alpha the launch it felt the project deserved.

Lost Alpha is just one of many significant mods for the game.

Nearly three years after the inadvertent release of Lost Alpha, the Developer's Cut came out in April 2017. The parallels between this high-profile mod and the game it's based upon are striking: In late December 2003, a pre-alpha build of GSC Game World's S.T.A.L.K.E.R. was leaked to peer-to-peer file sharing networks. This was a version of the game that was never meant to be played by the public. The final version of S.T.A.L.K.E.R. launched four years later. It's almost as if S.T.A.L.K.E.R., seemingly a now-dormant franchise, is cursed.

For Dezowave, however, it's a case of job done. "If we want to compare Lost Alpha to our demands, then yes, it's close, very close to it," Munkacsi says. "If we want to compare it to GSC's original plans, it's not entirely close, but it contains lots of aspects."

Now, the future of Dezowave seems unclear. With few members, the group looks set to scatter to the wind. "Most of us are over 30, some of us are even over 50, and we are all sitting in different countries with different time zones," Munkacsi says.

The S.T.A.L.K.E.R. series is a rarity, but its loyal fanbase is determined to keep the game alive. It is a determination rivalled only by the humongous communities of Skyrim. Lost Alpha is but the latest in a long line of attempts to reshape the series' experience. Fans all have their own idea of what makes S.T.A.L.K.E.R. the game it is, but no matter the project, when it comes to S.T.A.L.K.E.R., the results are always fascinating.