News of a Firewatch movie has popped up. Awesome. This has the potential of being something really neat, or a total disaster.
To make it the former, the designers and writers and going to have to overcome several hurdles. The biggest being--their egos! Too much of the actual game's "failings" seemed to stem from the designers having so much fun, and tossing ideas around (at this point, I recommend you watch the game again, in the new audio-commentary version; this includes comments by the designers and is very illuminating), that when they realized several elements that didn't quite work, they simply hamstrung the thing together to get it to completion.
Movies are different than games. 2nd hurdle they need to realize. If the movie doesn't have a winner, loser, or both, people are not going to recommend it to others. In Firewatch--the game--there is no "real" winner or loser; unless you count the Goodwin boy. And while one could argue that that's "another story" it might just be that that might very well be the key component of making Firewatch the movie, better than the game.
Thirdly...the character of Delilah has to be resolved. In the game, there is too much dialogue floating about (designed to respond to specific comments by Henry and/or the player) that she can never truly be pinned down as to her motives. While nearly all mystery stories, movies, etc., usually end up offering the reader-viewer some completion at the end, to not do this (again) in Firewatch, would be a mistake.
Those are a few concerns regarding Firewatch as a potential movie. Are they valid? I dunno. In the words of Delilah "Why don't you choose?"