The game plays to a large point like civilization 2 - with its flaws and merits, even with rather similar graphics.
Some aspects of the game play are vastly improved - larger number of technologies, including futuristic ones, cities built not only on the ground, but also in ocean or in orbit (yes, futuristic technologies), there's some interesting micromanagement like a chance to change the spending on army by choosing "readiness level" or fiddle with workday length and wages for worker, getting a payoff from high happiness, number of units withs special abilities (slavers, priests, diplomats)... Generally said, this is all good, much better then the old civ2 is.
The reason why it gets three stars rather then five is the interface which is... terrible. Only after playing CtP I've truly realized how clean and easy the civilization city screen is, with all information neatly laid in the same screen (rather then on taps like here), with resource imput easily understood. With units easily switched and cycled between, with pop-ups after city finished production. Here you will regularly discover huge armies of diplomats that brewed in a city, because you didn't notice production was finished, cities will stand idle for turns when they production queue runs out etc. Sure, it is possible to all the info - but where civilization presents it on silver plate, here you really have to deserve it. This, more then anything else, made me finish the game only a handful of times, as opposed to dozens in case of civilization.
Bottom line - if you like civilization and would like a richer tech tree and a bit of fresh air, go for it, twice so if you're hardcore type willing to check out several tables before each clicking of "end turn" button. If you look for streamlined, easily flowing game with user friendly controls, look elsewhere.