Users found in the LinkedIn profiles of some Valve employees information about the next project of the American corporation, which may well be a new part of Portal.
For example, on the page of Michael Anderson, the company’s ex-designer, it is indicated that he was working on an unannounced game that contains puzzles. It also boasts a unique gameplay that is very different from what is now presented in the industry.
Anderson worked on this project in 2021. So we can assume that it has been in development for almost two years. It is not clear whether this is a completely new IP or a continuation of the well-known series. However, its description fits Portal 3, as the previous parts consisted entirely of puzzles and had an unusual gameplay based on the use of a portal gun.
On the other hand, some parts of Half-Life also had mysteries, and their gameplay can be called ambitious. So we can’t rule out the possibility that a full-fledged Half-Life 3 is in production.