I don't think for one moment hard-core or action gamers are going to like this but for a lot of people looking for a slower, easier, atmospheric experience this is wonderful.
In many mainstream games, after completeing 'the mission' I have enjoyed much more time wandering, exploring, discovering and sometimes just sitting and watching and this story feeds that feeling.
Firewatch does indeed have a plot, tasks to be completed, mysteries to be solved etc but it's beauty is in the sense of place, exploring the woods, talking over the radio to your unseen collegue, scrambling along mysterious canyons, admiring lakes and picking your way, map in hand, to new glades and supply dumps. And when you get chance, you can stop a while on a rocky cliff ledge and look over the glorious landscape of forested mountains as hazy evening sunlight bathes the view.
I love this 'experience/story', while I almost hesitate to call it 'a game'. Just as you might pick up a book to immerse yourself in a beautiful place you love, wandering through Firewatch takes me out of myself and to a place that makes me smile.
I'd love more 'games' like this.