“Survival” as a video game concept has evolved radically through the years, yet it rarely strays from the horror trappings established decades ago in primal genre prototypes like 1989’s Sweet Home and 1995’s Clock Tower.

The close relationship between survival games and horror themes makes the outliers all the more remarkable. And no outlier is quite so notable in its divergence from classical horror themes as Irem’s Zettai Zetsumei Toshi series, whose first entry appeared in the US 15 years ago under the name Disaster Report.

Disaster Report forced players to practice the same sort of cautious behavior as any other survival game. However, rather than pitting its hero against rotting legions of undead or shambling victims of a sci-fi plague pandemic, Irem’s adventure was grounded in mundane reality. Disaster Report’s looming, impossible threat had nothing to do with throngs of zombies. Even the game’s hostile human opponents lacked the nail-biting sense of danger that comes from Disaster Report’s true threat: the ruins of a city shattered by an earthquake.

Disaster Report came from Japan, a nation wracked by earthquakes. Director Kazuma Kujo, currently the president of independent studio Granzella, based the game based on his own experiences and losses.

”I lived in Kobe as a student,” told me in an interview several years ago. “The Hanshin earthquake happened after I had already left, but I had friends who died because of that earthquake, and it made me realize the horrors of earthquakes.”

While nowhere near as powerful as 2011’s Touhoku quake, the Hanshin quake left more than 6,000 people dead in the area surrounding Kobe. It remains one of the most destructive single incidents in Japanese history.

Kujo gravitated toward the quake theme due to hype surrounding the PlayStation 2’s power.

“I wanted to make something that took advantage of that,” he said, “and I thought it would be entertaining if I made a game where it wasn’t aliens and monsters attacking, but the city itself being a threat. There’s a novel written by Komatsu Sakyo called Nippon Chinbotsu [Japan Sinks]. It’s a story about all of Japan sinking and disappearing and how it might feel to lose the land that we live on and call home. Those are the kind of feelings I wanted to recreate.”

The game recreated the challenges that quake survivors face in reality. Everything in Disaster Report is presented in extremely video game-like terms — players spend a great deal of time collecting compasses, which here serve as a bonus item akin to Pac-Man’s fruit — but these details all stem from genuine needs that emerge from people trapped in the wreckage of a devastated city.

Disaster Report might remind you at first of a modern-world take on Sony’s Ico, with players picking their way slowly through puzzle-like 3D spaces, often with the help or hindrance of computer-controlled companion characters. As with Ico, traversal comprised the bulk of Disaster Report’s play time, your on-screen avatar working alone or in tandem with an ally to pick through the ruins of a collapsed city and escape to safety.

Occasional bouts of combat pop up from time to time, and those are also likely put you in mind of Ico: they’re clumsy and distracting. This is a game meant to test your resource management and environmental puzzle-solving skills, and it falls short when melee combat or shooting intrude into the action.

Sunstroke, dehydration and unstable structures present Disaster Report’s greatest dangers; players have to mitigate the former by seeking water, while the latter make each screen of the game environment into a potential death trap that can shift beneath your feet without warning.

Conversely, a simple source of fresh water creates the same sensation of relief as an ammo cache or typewriter save point in Resident Evil. Jump scares come not from monsters, but rather through screen-shaking aftershocks that destabilize the already crumbling urban landscape. Other characters collaborate and compete with the protagonist, working together to escape the ruins yet not always seeing eye-to-eye. And while there’s still a human threat element for players to contend with, these amount to little more than contractors trying to cover up governmental negligence.

Disaster Report admittedly didn’t pull off its grand ambitions without a hitch. The much-vaunted PlayStation 2 hardware turned out not to be quite as mighty as promised, so the game suffers from some visible technical shortcomings.

This is a game meant to test your resource management and environmental puzzle-solving skills

Despite containing rudimentary 3D graphics for its era, Disaster Report’s frame rates often dip low enough to affect playability. It also predates the advent of modern control standardization, so its interface feels decidedly awkward in comparison to more recent games.

Happily, its sequels (one of which came to the U.S. as Raw Danger) would improve on Disaster Report’s shortcomings while building on its central premise of survival. By the time the third game (a Japan-exclusive PSP release) rolled around, the series had become a central pillar for publisher Irem. ZZT-themed earthquake simulators dominated the company’s booth at multiple Tokyo Game Shows, and the developers increasingly treated the games as more than just light entertainment. Each new entry explored different facets of urban survival in the wake of a natural disaster.

Unfortunately, Disaster Report’s sequels were themselves done in by an earthquake. The fourth game in the series was slated to launch for PlayStation 3 on March 10, 2011, a day before the Touhoku earthquake struck.

Production difficulties had already delayed the game until later in the year, Irem decided to cancel the game altogether after the quake. The company was ostensibly worried about the optics of releasing a game about earthquake survival after so many people had been killed or displaced by the real thing.

However, Kujo claims Irem simply wanted to get out of video games and into the casino business, and the quake provided a remarkably convenient excuse. (That Irem has only published archival releases and pachislot titles since 2011 bears out his claim.)

The circumstances of ZZT4’s cancelation ultimately galvanized Kujo. “I originally made [Disaster Report] for entertainment purposes,” he says. “But, about the time we made ZZT3, I started becoming aware about how the fans were finding the information helpful and tried to incorporate that type of information into the game. And, when I saw the effects of what happened [in Touhoku], I thought that I could make a game that is even more informative.”

Kujo’s current company, Granzella, bought the rights to the ZZT games from Irem several years ago and reissued all three titles on PlayStation Network in Japan. Meanwhile, the developer claims to be finishing up a rebooted version of the fourth game — the closest this survival series has ever come to grappling with zombies.

Initially slated for launch in February 2017, the current incarnation of ZZT4 still hasn’t amounted to much of anything beyond a website and occasional rumblings from Granzella. Perhaps it never will.

Permanent cancelation would be a shame, though. A decade and a half on from Disaster Report’s initial debut, the series’ interpretation of survival gaming remains unique. Battling the diabolical threat of sunstroke will never have the broad appeal for gamers of backstabbing dozens of other people in pursuit of multiplayer supremacy, but the niche charm of Disaster Report is a big part of what makes it so unique, and so worth discovering, all these years later.