Semi-realistic aliens, yea. Well, more realistic than any other science fiction aliens, outside of Three-Body Problem. You miss what the goo actually is and what it's purpose is, if you stopped watching half way through season 2. All you saw was what human scientists were doing by experimenting or rudimental changing what they could with the original stuff.
Previously in this thread, people have said the books take even more pains to not stretch physics too much. For example, in the books (I guess) all the people in ship combat are immersed in fluid when making high G maneuvers, instead of the injections they get in the show.
Also, Hoss hating the best (or maybe second best) character in the show is a take worthy of Chuk...