Wasteland 2 is a forthcoming role playing game currently in development by InExile Entertainment. It's already available for Windows through Steam's Early Access program, and it comes to Mac tomorrow along with a new beta release for Windows. Via Kickstarter:
We've made great progress on this beta update and are currently putting it through final balancing and testing touches: it will go live on Steam next Monday, the 24th ... OSX owners will be happy to know that Wasteland 2 will be available for their platform at the same time as we're putting the beta update out.
Wasteland 2 is the sequel to a game that originally appeared in 1988, considered the progenitor of the classic post-apocalyptic game Fallout. It features an overhead perspective with a focus on tactical combat.