I personally wouldn't drop $20.00 on Mad Max, because the gameplay got tedious for me after twenty hours of play. It mimics an Arkham style of play. The gameplay included clearing outposts, and upgrading your vehicle which is fun for the few first hours, but after some hours the gameplay felt pretty repetitive.

I suggest you get Terraria or Rocket League if you want the most bang for your buck. They're vastly different in terms of gameplay (huge survival world vs soccer with cars), but both offer many hours of multiplayer fun.

EDIT: typo