The familiar turrets can be seen to oppose players, as the new trailer combines the physics breaking world of Portal with the more traditional puzzle type games that coerces players into finding creative ways to build bridges to traverse hard platforms.
It's not a joke or a quick cameo: there really is a new Portal game coming out.
GLaDOS returns too, likely to goad you with every one of your failed attempts.
Valve, Headup Games, and Austrian game developer ClockStone Software announced a new collaboration earlier today that will give fans a new take on the hilarious puzzle experience Bridge Constructor. They can fail due to weight and physics etc, so you can also purposefully cause crashes and bridge collapses to witness some havoc.
The series is a spin-off of Valve's Half-Life series, with the original game forming part of compilation The Orange Box alongside Half-Life 2: Episode 2, which revealed the narrative ties between the two series. You solve puzzles via clever placement of these portals and jumping (or walking) through one to come out the other. This will be the first Portal-related game that has been released for mobile platforms. Additionally, GLaDOS singing Jonathan Coulton's "Still Alive" is. It appears to be a new, Portal-themed version of Bridge constructor. While Portal 2 was the last entry for the series, and released for the PC, Xbox 360 and PS3 in 2011.