I've been playing it. I grabbed it for $30 (knocked off $20 using vouchers on GMG) and it was the right time, I really felt like getting into a Civ game.
The real changes in the gameplay aren't immediately evident until you get well into the game and realize them. The game feels a lot like Civ5; it's easy to feel like this is Civ5 in space since it borrows quite a bit from Civ5 and it innovates on some of the mechanics, for example the tech tree is now more of a tech web, but it takes some leaps and has you rethinking how you used to play Civ games.
With gameplay, compared to previous Civ games, this is the fist time I've had to really focus on having a decent military force because the planet surface is relatively hostile. You have many more hostile aliens (like barbarians) scattered about and then you have to consider the mists of miasma and your unit positions (in miasma, your units lose 10 health per turn and aliens gain 10 health per turn). You definitely need to be more strategic about exploration as well.
I'm still exploring the game, just as I am exploring this new world, but so far I'm loving it and I keep getting stuck in the late night "just one more turn" dilemma.
