The Valve News Network—obviously, not a Valve-run news network, but rather a thorough YouTube channel dedicated to all things Valve—has released a new video, about Portal. The Unseen History of Portal delves deep into the making of the classic puzzler, presenting a bunch of unseen footage and little-known info in the process.

SEE Portal's origins as student project Narbacular Drop, WITNESS its evolution into a Valve property and into the Source engine, and BEHOLD what came after, i.e. cake. PC Gamer even gets a (very) brief mention—did our site really used to look like that?

Science has gone too far. One minute you're enjoying a spot of light testing, the next you're trapped in the infinite, unknowable void between dimensions, outside of space and time itself, staring at the side of your own head through a kaleidoscope. It's remarkable no one has tried it before.

YouTuber CrowbCat used the Portal 2 SDK to set up a test chamber in which two portals could be brought face-to-face. In keeping with scientific spirit, he jumped on in. Somehow, the game doesn't crash and the result is fun to pass off as part of the lore of the universe. In one of an infinite number of Portal timelines, Chell is lost in the orange and blue folds of the fabric of reality. What a way to go.

Joy to the world, the tests are run! The result is a spectacular three-minute Portal carol built in Source Filmmaker by Harry 'Harry101UK' Callaghan. The turrets—including the Animal King, naturally—have come together at this special time of year to spread neurotoxin to the tune of Mykola Leontovych and Peter J. Wilhousky's Carol of the Bells.

Callaghan did the voices and music himself, with turret rigs provided by August 'Rantis' Loolam, which is an exhausting array of talent and an indictment of my own sorry skillset. You can find his YouTube channel here, and the song is available on Bandcamp.

Portal Stories: Mel is a massive mod for Portal 2 that will be released on Steam on June 25. Representing four years of work by a dedicated team of modders, it contains five chapters, a custom story and original voice work, lots of new assets, and of course a buttload of new test chambers and levels to explore and solve. In other words, it's entirely new Portal game.

The mod begins with a little Half-Life flavor (a long tram ride) and then a scene reminiscent of Bioshock: a stroll through a town built by Aperture Science to house its employees. It's 1952, when Aperture is still a plucky startup with a bright future, and the facility beneath the town is filled with scientists, though unfortunately they're all out of reach so you can't actually interact with them.

Aperture being Aperture, it's not long before something goes horribly wrong. Having been preserved in a cryo-bed, you awaken to find the facility in a shambles. The environments are massive and incredibly well designed with tons of detail, and there are a few professional-looking cinematic sequences. The mod assumes you know what you're doing when it comes to portals: there's no slow build-up to the puzzle-solving as in the Portal games themselves. You get the portal device and are immediately faced with some challenging rooms to solve, and they remain tough for most of the game.

As a Portal player, I'm a bit more fond of the types of puzzles without searing laser fields and acid pits: I like to experiment freely without worrying about dying and having to start over. Many of the puzzles in Mel, however, are of the more fatal type, to be approached carefully and methodically. Gels, cubes, lasers, switches, turrets, and force fields are the main tools and obstacles you'll face in the sprawling and complex levels. Naturally, you'll engage in a showdown with a malignant A.I. near the end of the game.

As far as voice-over work goes, one actor provides a pretty good Cave Johnson impersonation, and another voices Virgil, the personality core who accompanies you through the majority of the game. I didn't find the humor particularly effective, and much of Virgil's dialogue feels like overkill as it's based around him encouraging you to find a way out of the facility. You'd be doing that anyway, right? At the very least, it's done with a lot of enthusiasm and an obvious fondness for the Portal series.

This massive mod is completely free if you own Portal 2, and provides around 6-10 hours of gameplay. Portal Stories: Mel will be available on June 25 via Steam.

Pinball FX2 developer Zen Studios teased a Valve themed announcement last week, and today we finally know what they are up to. Pinball FX2 will be getting an official Portal themed table towards the end of May or beginning of June. While it's not exactly Portal 3, it's definitely an amusing and detailed return to the Portal universe crafted by developers who are clearly fans of the series. Watch the video above for our hands-on look at the upcoming Portal table for Pinball FX2.

For those of you unfamiliar with Pinball FX2, it's a free pinball game on Steam that sells individual tables as DLC. Tables can be demo'd briefly, but eventually need to be purchased if you want to play them for an extended period of time. Zen Studios has done many licensed and themed tables in the past, but this is the first time the developer has worked with Valve. The level of detail on the Portal table is impressive, and makes me hope that this won't be the end of Zen Studios' partnership with Valve.

Reddit has dug up some brief footage of the Portal environment Valve used to demo the Vive headset to GDC attendees recently. It's taken from a talk by Valve's Alex Vlachos on advanced VR techniques, which he used to boast about the fidelity the development team were able to achieve using high-poly models in a small environment.

The demo has you repairing Atlas, one of the co-stars of Portal 2's co-op mode. He explodes into his component parts and you have to fix him using the Vive's motion-tracked controllers. Maximum PC caught some of Vlachos' commentary during the footage.

"Because you're in this tracked space with this guy and you can walk up and he has all these moving parts. The moving parts alone are like 600,000 triangles or more. I forget the exact number, but there's a lot of triangles there which means you can get incredibly close to this guy and all these parts and see the shape and the details."

Valve programmer later Tweeted confirmation that the demo was built in the Source 2 engine. Valve also announced that Source 2 will be free, but users will have to sell their game through Steam (though are free to sell the game in additional ways if they wish).

We've tried the VR demo. Here's what it's like to play.

At GDC today, Valve has been showing off a demo of HTC's new virtual reality headset. We're going to see the demo tomorrow morning, but we already know a lot about it from our colleagues' reports: it looks a lot like a new Portal. It is not a new Portal.

I reached out to Valve and asked for a comment on how the demo is being interpreted: CNet, for instance, said it "sounds like" Portal 3, while Tom Parsons of Stuff claimed that he had actually played a Portal 3 demo during his Vive hands-on. I told Valve that I was skeptical that they'd soft-announced Portal 3. Valve director of marketing Doug Lombardi responded, "We have not."

I followed up to be absolutely clear, asking, "The demo being shown does not represent a prototype or indicate any plan for a new Portal?" Lombardi replied, "Correct. Just a demo." So no, this isn't Portal 3. It's just a tech demo until we know more—and I suspect Valve is just having fun with some existing art.

The above trailer is the work of Portal 2 machinima-maker 'Harry101UK'. The mod powering it is Portal Stories: Mel. It's a new story, based in the Portal 2 universe, about new protagonist Mel and the new personality core that she's travelling with.

The mod boasts custom textures and animations, and over 20 new maps. It's also been Greenlit—meaning it will be made available directly through Steam. And, unlike last year's Aperture Tag, it will be entirely free.

For more, head over to the mod's Steam page. Portal Stories: Mel is due out early-2015.