Massive 12TB Steam leak reveals decades of unreleased games — archived files include unseen Half-Life 2: Episode 3 builds and assets

A massive 12TB archive leaked from old Valve servers has revealed development files dating from 2003 to 2013. These pre-release versions serve as time capsules, preserving game states before significant changes occurred. The leak includes early builds of Portal 2 and unseen assets from the long-cancelled Half-Life 2: Episode Three. Fans are currently analyzing the archived data to uncover traces of these unreleased projects and explore the company's historical development process during that decade.