The less you know about this, the better.

If "Bones - Low Roar" moment doesn't hit you, I don't know what will.

There can't be enough words to describe this.
The environment and landscapes are a wonderful sight to see where you can go to any place you see in the world.
Soundtrack is a lovely vibe which sets the bar quite high and complements the game very well.
All the main characters have done an excellent job in the narrative & scenes which have striking visuals and cinematography.
Nothing compares to the online mode, you'll feel more inclined to help others than yourself. Although you don't see other players, you'll be seeing the things they leave behind to help others. You can contribute towards certain structures along with other players which benefits everyone. You can claim items donated by others or donate items yourself to help others in their journey. A very useful & rewarding system.
Best played on a controller with vibrations if possible. Nicely implemented vibrations where you'll feel resistance depending on the terrain and the activity the main character is doing.
Interesting gameplay mechanics with lots of structures to build which helps make tasks a bit easier. There are vehicles like bikes and trucks for travelling.
Lots and lots of stuff to read, well thought main-quests & a unique concept you've never imagined before. "Interesting" doesn't do the questline justice. You'll have to see for yourself. Story is linear with some 4th-wall breaking moments here and there.
Standard orders or misc quests can be repeated to get better rewards from the people you meet in the world. Side-quests (jobs for the main character) are limited but enjoyable.
Combat is decent but it does feature lots of weapons. Melee combat is a bit satisfying and fun which may be repetitive to some extent.
User interface and experience are well enough on both controller and keyboard. Optimisation is great to say the least.
You'll be giving likes and getting likes, that's the "XP" system. There are no skills nor currency in-game. Instead, materials are used to craft items and are easier to come by. Difficulty can be changed at any time.
Also, everyday is bring your kid to work day!

All in all, a masterpiece of a game. A favourite.