I feel like you could make a decent to good mini/series about Portal. There's plenty of lore, and if whoever made it tied into Half-Life somehow, that would be even cooler (it could probably literally just be a quick mention of Black Mesa or something on a whiteboard somewhere).

Each episode could be a "test chamber" or two, and each episode ramps up the action, stakes, and questions.

Tease Ratman; maybe the Cake; make the turrets extra little characters (kinda like the Battle Droids in TCW); maybe even have some Personality Cores to provide some extra opinions/dialog about what's going on, like Wheatley, but more than just him.

Edit: I bet J.K. Simmons would be up for coming back for more Cave Johnson shenanigans. Idk about live action, but some more recordings would be fun.