What’s it like playing an augmented-reality game on the Microsoft HoloLens? Expect it to be a much more physical experience than virtual reality, a HoloLens developer says – and possibly a bit hotter, too.

Microsoft has already unveiled some of the first games and apps arriving on the HoloLens, and the developer edition has begun shipping. While Microsoft didn’t allow us to test the HoloLens ourselves, David Dedeine, who oversaw the development of the HoloLens games Young Conker and Fragments for Asobo Studios provided some insight. He says gamers should expect exploration and activity when playing Microsoft’s holographic peripheral.

Young Conker, for example, has users essentially leading a smartass squirrel via one’s gaze, collecting coins and evading enemies. The HoloLens will scan and construct the level based on the your room you’re playing in and the objects inside it. The kicker: With a different room, there’s a different layout. In Fragments, a crime investigation game, you’re asked to poke around the room, manipulate virtual objects, and talk to virtual characters.

But like VR, there’s a catch. With virtual-reality devices like the Oculus Rift, there’s the very real risk of motion sickness or nausea. That diminishes substantially with an AR device, as your eyes can fix on both real-world objects as well as virtual ones. The downside of AR is that its lack of tether to a PC means you’re hauling around a computer on your head – and as with a notebook PC, power and heat management are critical, David said.

In Young Conker there are even boss battles!

Those concerns don’t lessen David’s enthusiasm for AR. In fact, he relishes the experience of developing launch apps in such virgin territory. “I say that there is a continent of gaming, and VR is just a new peninsula on that continent,” he said. “AR is an entirely new continent.”

A number of journalists and developers have tried out VR devices like the Oculus Rift and HTC Vive. Far fewer have had a chance to experience the HoloLens up close – and those who have haven’t played any games on it. This is the first time any developer has revealed that the thing they’re worried most about on the HoloLens is heat – and, as you’ll see, it’s a concern that affects both comfort as well as the device’s ability to remain up and running.

Your room, underwater: a scene from Asobo’s Fragments game for the Microsoft HoloLens.

What HoloLens games are like to play

What’s perhaps most surprising about both Young Conker and Fragments is their length: six to seven hours for each, with a great deal of replayability on Conker, thanks to its ability to create different levels from different environments. Conker also includes additional leaderboard challenges where players can compete with one another.

The HoloLens works by “scanning” real-world objects into the virtual space, so the crux of your experience will vary from room to room. At the beginning of Young Conker, for example, the HoloLens will ask the player to launch the scanning process. According to David, the HoloLens can actually scan in a very large physical area, or “playspace”: 64 square meters, or about 680 square feet, though the number of objects in the scene will probably be taken into account. The smallest playspace is 3 square meters, he said.

Both Conker and Fragments will apparently be playable with just a HoloLens and a large empty space, but the experience becomes much more interesting when real-world obstacles and objects are factored in. Think about it this way: The HTC Vive asks you to basically reserve a 6x6-foot empty space for play. HoloLens encourages you to play within whatever space you’re in.

The Microsoft HoloLens needs to “scan” the room with its camera to create the levels for the game.

“All those experiences have been made so you can walk everywhere possible...and there is lots of feedback to let you know whether your playspace is big enough or not, and there is accuracy feedback, too,” David said. “Because while it might be big enough, [the scan] might not be accurate enough. So we give them accuracy feedback.”

Conker has traditionally been a “platform” series of games, starring a wise-cracking rodent who runs and jumps over various obstacles to move through the game. That mechanic will still hold true in AR, though the “obstacles” will be real-life objects. Gamers will collect items, fight villains, and run around on the tables, walls and possibly even the ceiling—as well as thin air. Players are essentially looking where they want Conker to go, indicated by a small arrow wedge next to his character. 

“So obviously you can play the different level, let’s say level one, in different rooms, and it will be different, but as soon as you arrive in level 15, it will be a different level than level one—even if it’s in the same room,” David said.

You can get a more visual representation of how Young Conker will play in this video: 

Fragments, by contrast, sounds like it will be a much more deliberate experience. In Fragments, you’re tasked with investigating a crime, but with a special talent: Your technology allows you to replay the memories of people associated with the crime, so you can piece together the story. You’ll need to physically explore your playspace, David said, and if you try to rush through the game, you’ll run into trouble.

Other crime-solving games task the player to poke around a crime scene by clicking and moving a mouse cursor. With the HoloLens, however, it sounds like objects may be physically hidden in the “real world,” so that you’ll have to explore. Game characters will actually sit on your couch. Yes, maybe we’ll become blase to the experience quickly, but this is something we’ve never even remotely experienced before.

Here, the Asobo team describes Fragments in more detail:

The HoloLens’s chief limitation is not the field of view

Yes, the HoloLens has limited battery life. Yes, the field of view has shrunk from the initial version. Yes, apps are restricted to about900MB of memory, and holograms appear best at certain distances. Yes,frame rates must be kept high to minimize vertigo. But David says the real concern is comfort, and especially managing heat.

For one thing, David cautioned, developers need to remember that the HoloLens’ 1.27-poundweight is always on the user’s head, pressing a heat-emitting CPU into one’s skull. And even if that’s not a concern, developers have to remember that the HoloLens will shut down a game if the device exceeds its preset thermal limits.

In this slide from Microsoft’s HoloLens developer documents, you can see what developers must do to minimize power. The key, according to Microsoft, is keeping the 1-minute moving average (the red line) down below the orange region. If it creeps up, the main foreground app will likely be shut off.

“The most important thing is to really be economical... you would never need to do this with console or PC – it’s all about consumption of energy, battery savings,” David said. “Even more important, it’s heat – to not make the whole thing get too hot, as it would be uncomfortable to the user.”

How well Asobo’s games minimise battery use is somewhat moot, though: Since the HoloLens battery life is about three hours, it’s probably impossible to play through one of the games on a single charge anyway. David doesn’t see that as a problem.

“Even if I believe that HoloLens is much better than VR, because it’s much more comfortable – that said, it’s something that people are not used to, like a TV or screen,” David said. “I might like HoloLens, but I will not use it like five hours in a row, like you would play an RPG. But I don’t think this will be an issue at all. I think three hours will be fine.”

And all that leads up to the HoloLens’ field of view, which in David’s mind is a secondary issue. To users, however, it hasn’t been: The first engineering version shown at Microsoft’s headquarters in January 2015 allowed users to see holograms in almost all directions. Today’s developer version projects holograms through a much smaller window, about the size of a smartphone held six inches away from one’s eyes. That leaves considerable space to the top, bottom, and sides of the “window” where holograms won’t appear.

“People make a big deal about the FOV [field of view] on the HoloLens, but for real, once you get used to it, you don’t think about it any more,” David said. 

Visual cues help point Fragments players to spots they can interact with using the HoloLens.

David said game makers can use obvious hints, such as arrows, to prompt a user to look in a given direction. But he’s found a more creative way to solve that problem: In Fragments, certain key objects are surrounded by virtual “shards,” which emit a tone and move when a user focuses on them. The game thus leads the user to where he or she should be looking.  

“Obviously, I would be the first guy to be super happy to have a better [FOV], but it’s a bit like complaining about the iPhone 1 being too small,” David said. “Yeah, okay – but it changed the world, and I believe that holograms will change the world, too.”