an informative review of Lost Empires: Immortals at Out of Eight. The review refers you to the previous Lost Empires game for certain details of gameplay that haven't changed drastically.
As for the ground combat, my understanding is that you can use troops to invade a planet but combat is automated (as is starship combat) - you can, I think, watch a replay if you choose.
I'm getting the impression that while GalCiv2 is arguably the current turn-based space strategy favorite, there are enough interesting aspects to make me consider Lost Empires: Immortals. Especially now there are enough improvements to the first game that would make it more manageable for the casual gamer - like smaller galaxies, better tutorials, improved interface.
In my galaxy, there's always room for more turn-based strategy games. What there isn't always more of is time.