Firewatch has been updated to a new version today on PC. You can find out the complete patch notes for this update from here.
This patch resolves an issue with third-party software that would leave no input to the game, blocking it effectively. In addition to this, some minor fixes have been implemented for Linux users. You can get the details on this update below, or take a look at the Steam forums.
Firewatch Update Patch Notes December 21
* Fix issue where some third party software would capture mouse input and block it from reaching the game. Also allow simultaneous gamepad and mouselook input without fully switching between keyboard and gamepad controls.
* [Linux] Fix issue preventing some users from launching the game.
