Civilization 5 was a masterpiece of sorts and Beyond Earth iterates upon the concepts brought to Civ5, adding a few things that are quite interesting and still creating the perfect 'one more turn' experience. You have more control on the direction your civilization is taking with some more customization features that impact gameplay in semi-significant ways and you have about half a dozen ways to victory. It's one of the rare games where I just started playing and emerged from a 8 hour session, only after victory was within my grasp. This was on very easy, but oh well.
After choosing a sponsor - your nation - which gives you a passive bonus that might influence the way you play the game and choosing other things - colonists, type of ship, kind of cargo you're bringing with you to the new planet - you are dropped into a quite hostile world where aliens lurk around and miasma deals damage to your units if you stand in it. The aliens are a bit tougher than the barbarians of old, you'll encounter various types of these things, including the Siege Worm, a mighty beast that isn't like anything you've faced in Civ 5. But at least the critters are not too aggressive and there are a few techs to help you keep them at bay.
The science tree is now a vast web where you start at the center and move to the outer edges by collecting science from your population each turn. Each node of the web has between one and three extra sub-nodes to it and some of the technologies give you affinity experience. This is one way you have to choose how your nation develops, affinities alter the way your cities look, the way your units evolve - you have to choose between two different passives when they do so - and ultimately, which victories you can trigger. I fumbled a bit with the science web and noticed only late in my game what I had to research in order to win, but that's because the quest system is a bit too discrete.
They've added quests to C:BE and they act as tutorials of sort but also as challenges, sometimes they will be quite simple - found an outpost - or others will be more complicated, like the steps needed to win the game. I think the quest system is mighty fine, but it should be more intrusive and point you towards the things you should be doing, maybe adding a quest ticker somewhere on the screen wouldn't hurt. And after you build or research certain things you have to make a decision between two choices and they both give bonuses without taking anything away, which is great.
They might have added a few things but a new coat of sci-fi paint still won't hide the core Civ mechanics. "Happiness" might have been renamed and reworked as "Health", "Money" is now "Energy" and every resource is space-age stuff, but you still make buildings, assign workers to make space farms, space generators and space terraforming on the map, trying to avoid Miasma - or use it at your advantage - and if you're into that kind of stuff, you can still micro-manage your population to fill certain roles - although I've always left it as it was. After you generate enough Culture, you pick a virtue, from four skill trees and picking more of certain trees or tiers gives you other bonuses. The virtues are quite powerful, but all players can use them.
You also can spy on other nations or use spies to bolster your headquarters a little, I have to say that this system confused me so I didn't use it much the first game I've played - except to boost my health, otherwise it didn't fit as the 'nice guy' civilization I was playing as. You can use it to steal energy, science, technologies, steal units and later on do more stuff as you progress in certain affinities. The ways to win are varied and the one I picked up was quite obnoxious, but I managed to pull it off while defending my continent against attacks.
I have to say that I don't understand the AI in these games so I always play at the easiest difficulties. Do they cheat? How do they manage to make these wonders way faster than I do? What do they really mean when they tell me I'm cool but then invade because I'm weak? What are these favors - tokens you gain by helping other nations when they need stuff - really useful for? And what about the little outposts that you can make trade route with? I've never messed with that stuff. Maybe I'm not a high level player enough to appreciate these things or maybe the game doesn't push them enough on me - if they're that powerful.
In any case, Civilization Beyond Earth is an amazing game built on already amazing concepts. It's hard to know where the Civilization franchise can go from here, but I'm sure whatever they cook up next will be awesome too.