Remember when Valve used to make new games, instead of just making insanely popular platforms for selling games (and hats and skins )? Valve promised a partial return to those days today with the announcement of a brand-new Portal game... that just so happens to be built as an expansion to Bridge Constructor.

OK, this might not be the Portal sequel that everyone was expecting or hoping for (that would probably require putting a "3" on the game's title, which we all know Valve can't do ). Still, the teaser trailer for the Bridge Constructor Portal —being developed alongside Headup Games and Clockstone Software—shows the same kind of physics-based gameplay that has made both Portal and Bridge Constructor into hits with fans of emergent design

And GLaDOS makes an appearance, too. What more could a Portal fan reasonably want?

Valve putting its development imprint on any game—even if it's just a licensing play for a spin-off to a non-Valve game—is newsworthy these days. It has been more than four years since the Steam-maker released Dota 2, its last full-fledged PC title. And while virtual-reality experiments like The Lab and an upcoming Dota-themed digital card game are nice, they're not really what longtime fans want out of a company known for franchises like Half-Life, Left 4 Dead, and Team Fortress (our own Peter Bright reports that The International crowd was "stunned" with "dismay and palpable anger" when the Dota card game was announced).

Valve did promise back in February that it was working on three "full" VR games that are "not experiments," but it gave no further details on what to expect since then. In a recent interview with Glixel , HTC Vive General Manager Dan O'Brien said that those titles were still in development and that Valve is "very committed; they are still committed to delivering on that promise." That's nice to hear, but it has to be weighed against Valve's long and spotty track record of broken game development promises

Bridge Constructor Portal hits Windows, MacOS, and Linux on December 20, with console releases planned for early 2018 and mobile versions at an unannounced date.