Not 'freemium' - there are no in-app purchases you need to make to keep playing.
Man Up Time has resurrected this 20-year-old masterpiece for modern Mac and they've made it absolutely free. That game was called Pathways Into Darkness. Before Halo, before Myth, before Marathon, way back in 1993, Bungie Software made a name for itself with Mac gamers with one of the most innovative first person shooters we'd ever seen (and really, we hadn't seen a lot of them, but we knew this one was cool).