I guess Shadowrun Returns, sort of. It's way shallower, but it's ok.
Sword of the Stars: The Pit... it's also a sort of, and it's a roguelike(but a really good, and high production value one, and still runs even on my 6 year old netbook).
Tactical squad shooters ok? UFO: AI is decent and also completely free.
There's some more tactical squad shooters as well, but straight up sci-fi isometric RPGs are few and far between. There's a few coming up that look interesting(Stasis, Wasteland 2, Project Eternity, etc), and a few amateurish looking indie ones that I haven't tried out(like Datajack), but there's really slim pickings in this genre.