Blame it on the mountain.

DayZ no longer has a release window for its alpha, a long awaited early build of the zombie action-survivor Arma 2 mod that is becoming its own game.

After missing several of his own deadlines for releasing the alpha, developer Dean Hall can't bring himself to announce another one to fans.

"I've made a heck of a lot of mistakes giving out release dates," Hall said in a meeting at Gamescom. "We don't have any release dates internally anymore."

Instead, he told Polygon, he and his team are going to focus on completing the alpha. The team has a checklist to work off of and once it's done they'll release the alpha. That list, he said, is down to a single check box: Networking.

That's despite the fact that last year Hall essentially rebooted the game.

"It was a very grim time last year," he said. "I took a bunch of massive risks.

"We realized we needed to redo everything and that didn't go over very well. In December we had nothing to show for it, nothing. It was very, very awful. Our worst fears were realized."

And then in March, in the shadow of his worst year, Hall flew to Kathmandu to start a two-month journey to climb Mount Everest. The timing was both terrible and serendipitous.

His trip to realize the life-long dream of climbing Everest had been planned the year before at a time when he was sure his work on DayZ wouldn't be as lengthy.

"I did need a break, he said. "But in our wildest nightmares we didn't think DayZ development would still be going on."

Hall went to the CEO of Bohemia Interactive and told him he was thinking of canceling the trip, that it was really bad timing.

"He told me, ‘If you pause your life to work on DayZ, you're going to keep putting off everything,'" Hall said. "I'm glad I ended up doing it, but I still haven't had time to reflect."

Hall's harrowing trip, punctuated by work on the game at base camp (and not a little time playing the original XCOM on a tiny laptop), didn't include a lot of post-climb downtime.

But it was during an overnight stay at a hotel in Kathmandu, a single evening that bridged the gap between his time spent climbing Everest and his return to work, that Hall had an epiphany of sorts.

"I remember opening the door after coming straight from basecamp after two months on a mountain and thinking how huge the laptop looked," he said. "I looked at my laptop and reflected. One moment I was a soldier working on a hobby project and here I was 12 months later working on a big gaming having just climbed Mt. Everest. It was amazing. I thought about what was important and what mattered. I decided I wanted to make the game I wanted to play, even if it meant only 1,000 played it."

Forty-six hours later, Hall was back in Prague, back at his desk, working once more on DayZ.

Before that moment in the hotel, Hall said he was worried about losing momentum with the game, but now he's mostly worried about making the sort of game that DayZ's players deserve.

And now the game is once more almost complete, at least the alpha. Once the alpha ships there is the beta to work on and finally the game to ship.

Even though there is still alpha and beta to finish developing, Hall is already thinking about other things he might include in the retail package.

For instance, while a core concept for the game is the idea of immersive, player-directed story telling, he's thinking about hiring writers for the game.

"But that's more for 1.0," he added.