I just played through Firewatch and loved it. The game only clocked it around the 4 hour mark for me, but it was wonderful. I'm so happy when a dev tells their story and then wraps up the game. This is the perfect example of a game that doesn't need to be 8+ hours to be worth the money.
In Firewatch you get a little bit of backstory about your character and then start your first day on the job of watching for forest fires from your tower. Your only line of communication is through a walkie-talkie to your direct supervisor and that's where the majority of the narrative takes place.
But things quickly start to happen that you need to go investigate. Most of the game finds you wandering the wilderness around your tower digging into things that are going on. You use an actual compass and map along with a limited gear set to traverse the terrain.
Not to mention the in-game disposable camera! It only has around 20 shots, so make them count. At the end of your game you get to see all the pictures you took and it even generates a webpage where you can go download them. That screenshot above is a picture I took in-game with the camera during my playthrough.
It's an amazing game for explorers and for narrative driven gamers. I haven't had a game grab me and amaze me like this in such a long time. I'm so happy to have found a game that clicked with me so easily.
I know that the price point of ~$20 matched with the playtime of 4-6 hours will drive some people away, but I felt like it was worth every penny. I already know that I'm going to end up replaying it very soon.
I highly recommend this one. Check out Firewatch. It's out on basically every major system today.