I was playing star trek online for a while, I actually bought it when it came out but its f2p now, the space combat is excellent I think, all tactical stuff involved, the ground combat isn't to great to me, I mean its ok, but not outstanding, its been out since 2012 and there's loads of missions they even have "seasons" like the tv shows did, and you have to finish a season to work the next, plus all sorts of side missions, exploration, pvp etc.
if you're a star trek fan then you'll understand this - its set in the pre JJ Abrams universe so after star trek nemesis, but set after romulus was destroyed, so whilst nero, khan, spock etc are fighting in the new parallel universe the old universe has carried on

Federation is at what with the Klingons once again, the borg made a comeback, as did other familiar species from the star trek universe. Worth a look