According to Star Wars: The Force Awakens director J.J. Arbrams, movies based on Half-Life and Portal are currently in the works. Back in 2013, the producer of 10 Cloverfield Lane and Star Trek Into Darkness posted that he and Valve's Gabe Newell were working together on movie and game projects.

And now, speaking recently with IGN, J.J. Abrams confirmed that the movies are in development and that writers are working on both of those stories.

Back in 2011, 10 Cloverfield Lane director Dan Trachtenberg released a fan movie for portal titled "Portal: No Escape in 2011".