Simulation games have built up their reputation by using the indomitable freemium method, which allows users to play without paying a cent or optionally play by buying hundreds of dollars worth of in-game currency and upgrades. Although some prefer not to invest in these casual time-wasters, the fact that they’re utterly fun is downright indisputable. Moonbase (free), the first title from South African-based development firm Maxxor, employs this powerful business model, and it’s undoubtedly got hours of fun packed in for any gamer.