Don't know why this game is Underrated. This game is way better than known popular action adventure games like Grand Theft Auto (GTA), Red Dead Redemption (RDR) and Watch Dogs (WD), especially the gameplay of controlling Mad Max, the game's protagonist. The Controls are better. Whenever you try to attack enemies in this game, Max attacks them in a Karate looking style. I like how The enemies in this game are strong, ferocious and ghost looking. You can even travel through Dark Tunnels to fight enemies, which would make you feel the thrills. The Game’s Villain, Scabrous Scrotus, is fleshed out and Robust. In the beginning of the game, Max meets a old mechanic named Chumbucket, and they become close friends later. While this is a good action adventure fighting game, you will see a emotional connection between Max and Chum. While Max ventures out in combat, Chum guards Max's car and repairs it, but they both stay and talk to each together when driving. But during the final Scrotus battle, it's sad to see that Chum dies.
I even like how the location featured in this game, the Old Australian Wastelands, is huge and has the Day, afternoon, evening, and night cycles. Whenever I explore the Wastelands, It reminds me of exploring Old Russia a.k.a the Cosmodrome and Meridian Bay Mars.
(If You don't know, Old Russia and Meridian Bay Mars are both selectable, explorable locations featured in a First Person Looter Shooter Game Called "Destiny 1").
I definitely recommend giving this game a try.
If you really want a really good underrated open world fighting game like this, I also suggest Sleeping Dogs.