Portal: Revolution

Portal: Revolution is a 2024 fangame and prequel to Portal 2, developed by Second Face Software. Work on the mod began in 2016, and it runs on a heavily modified version of the Source engine that, according to the developers, enables features that would be impossible to implement in Portal 2 itself.

Set before the events of Portal 2, the game puts players in the role of an unnamed test subject who attempts to activate a device capable of restoring Aperture Science’s decaying test chambers. As with the official titles, Portal: Revolution is a first-person puzzle-platformer built around solving test chambers with the portal gun.

The mod expands the classic mechanics with several new elements, including a gel-cleansing shower, paired cubes that help redirect laser beams, and Pneumatic Diversity Vents that can vacuum up objects — including the player — a feature cut from Portal 2 during development. Certain chambers also feature power-cut switches that remove laser hazards while simultaneously disabling helpful devices, adding an extra layer of strategy.