Mad Max is described as 'Survive the Wasteland as Mad Max, completing treacherous missions and scavenging for supplies to build the ultimate combat vehicle'. There are four games similar to Mad Max for a variety of platforms, including Playstation, Steam, Windows, Xbox and Bethesda Launcher. The best alternative is Fallout. It's not free, so if you're looking for a free alternative, you could try Crossout. Other Mad Max like games are Borderlands (Paid) and Rage (Paid).
Fallout is an RPG game that is occurring after a nuclear war what destroyed the entire world as we now it. But there was a few people that survived in "Volts" and they created the "new world". Represent entire series of Fallout games including Fallout, Fallout 2, Fallout: New Vegas, Fallout 4, Fallout 76.
Borderlands is a first-person shooter mixed with role-playing game (experience, specializations) that takes you to a mysterious planet, looking like a futuristic Wild West. Represent entire series of Borderlands games.
Crossout is a massively-multiplayer game of mechanic combat in a post-apocalyptic world. Craft your own battle machine from scores of interchangeable parts and drive them into combat with other players in online PvP battles.
Developed by id® Software, the creators of DOOM® and QUAKE®, RAGE is a groundbreaking first-person shooter set in the not-too-distant future after an asteroid impacts Earth, leaving a ravaged world behind.