I can hear the alien breathing.

I've played lots of videogames, lots of run-and-gun shooters in which I happily charge down a corridor into certain death. Not this time. I've got my back pressed against the wall of an abandoned spaceship, and I'm inching down a hallway, my head darting left and right, looking for danger everywhere.

And I wonder, is this the one? Is this the Oculus Rift demo where I rip the headset off my face and bolt, terrified, out of the room?

I don't get scared by horror movies or horror videogames. Sure, you can startle the hiccups out of me with a well-timed jump scare, but that only proves my lizard brain is firing on all cylinders. For the most part, I feel a pronounced disconnect between the frightening scenario onscreen and the safety of my living room. I don't understand how some of my friends cannot bear to even pick up the controller and walk down a hallway in Resident Evil.

So it came as quite a surprise when I found myself so truly on edge that I almost lost it while playing Sega's Alien: Isolation demo on Oculus Rift. The game, shown at E3 this year, is a custom VR prototype based on the survival horror game coming to PC and consoles October 7. More than that, though, it's another compelling demonstration of how Oculus Rift has the potential to make gaming so immersive that the fantasy becomes reality.

Sega won't say whether it plans to make the Oculus version a full-fledged consumer product, but it would be crazy not to. I'd played VR demos in which I truly believed I had been transported, but also demos where I felt like I was watching a bad movie on a really huge screen. Alien: Isolation was very much the former. The clever hook of the console game—exploring a lonesome world inhabited only by you and a lone alien, which you spend the entire game avoiding—is a perfect fit for Oculus.

"Like everyone else, we got very excited by the idea of Oculus Rift when it was first going into the Kickstarter," said Al Hope, creative lead of developer The Creative Assembly's console division. His team already was working on Isolation when Oculus launched its Kickstarter drive two years ago, and it seemed the two would work well together. Several Creative Assembly developers backed the crowdfunding drive, and they got Isolation running on Rift as soon as their initial development kits arrived.

Sitting down for the demo, I endured the now-familiar ritual of having an Oculus rep place the development kit over my head before clamping a pair of headphones over my ears. And then it began.

Suddenly, I'm walking down a quiet, seemingly deserted hallway on an abandoned spaceship. The demo runs on DK2, the latest version of the Oculus development hardware, so it is clean, vivid, smooth. Lifelike, in other words, and utterly believable.

I'm admiring the steel grey detailing of the hallway, the hum of the distant machinery reverberating through the ship, and how it all feels a bit like a VR version of Metroid Prime when something catches my eye. Uh, is that a dead body at the end of the hall? Yes. Yes, it is. I start getting anxious: Is this guy going to come back to life and jump-scare me? How close do I want to get? I approach him, cautiously. I find myself suddenly worrying about what might be behind me.

"Hey, turn on your flashlight," the Oculus rep says, just loud enough to break reality into this alternate world. Like a moron I do. Holy crap now there's light shining on the dead guy's face. He's slumped against a console, his vacant eyes staring ahead down the hallway I'd just walked. I don't like looking at this. It's a queasy, uncanny sensation. I move on, more slowly.

Creative Assembly

The Rift added a level of interaction and immersiveness to Alien: Isolation that even its developers did not expect. There's a crate in the hallway. As in console games, I can press a button to crouch behind it. I don't think to do so, but Hope told me later that I could have lifted my butt just a bit, elevating my head and peering over the crate without without giving away my position.

"You can just, millimeters over the top of the environment, peek at the world around you," he said. More such opportunities revealed themselves to Hope and his team as they play-tested their game with Oculus added in. A pile of massive concrete pipes strewn about a construction area provide a measure of cover in the console game, but Oculus lets you lean in and peer through individual pipes. You can hide in lockers like a frightened nerd in the console game, but Oculus lets you lean toward the vents in the door to glimpse the hallway beyond. While crawling through an air vent, you can crane your neck to look around the corner.

These aren't features Creative Assembly deliberately programmed into the game's design—they simply happened once they dropped Oculus support into their existing code. As they come upon these fortuitous accidents, the team is polishing them up so they work even better. "It's a really physical experience," Hope says.

I was about to learn just how true that is.

>I inched sideways down the corridor, my head darting left and right, scanning for threats.

After I determined the dead body was not going to do anything, I saw something that surely was: H.R. Giger's unmistakable alien, wandering the hall in search of prey. In search of me.

For now, it didn't notice me. But I was on alert. I was looking everywhere for an escape route. I wanted to be anywhere but here, inside a spaceship with it. My brain started fighting itself. I had to consciously remind myself it wasn't real, it was just a game. And in that moment I started to think about the videos I've seen of grown men playing horror games on the Rift and tearing the headset off in terror. I contemplate what would happen if I did exactly that.

I continue down the hallway. It's no longer the casual saunter I'd so easily affected when the demo began. My back is to the wall, and I am inching down the corridor, trying not to make the slightest sound, my head darting left and right, scanning for threats. And then it happens: The alien finds me. I turn to my left to see him skittering toward me on all fours.

I didn't think to run, and wouldn't have gotten far if I had. It raised a spindly hand, claws sharp as razors, and brought it down. Game over.

I removed the headset, calmly, and pondered what I'd just experienced. After getting over my initial feeling of accomplishment over having mostly kept my cool, I was just blown away by how quickly and thoroughly Isolation on Oculus had pulled me into the experience, and shifted that experience from "hey, cool, virtual reality!" to something approaching actual fear.

"It's really interesting, going to watch people play and seeing them initially look around quite naturally, being interested in the environment," said Hope. "And then as the alien gets closer, you see their body physically react. They become tense. And then when the alien does ambush them, they reel back physically in their seats." One player, he said, upon being attacked by the alien, threw their head back in a desperate attempt to avert their eyes from the carnage.

And yes, they have had testers rip off the Rift, throw it across the room, and run out screaming.