Bottom line up front, price dropped from $59.99 to $19.99 for a reason. This game is worth MAYBE 7 bucks, and should have just been an addon to civ5.
I rarely write reviews, but I really hope this discourages someone from buying this game, because CLEARLY the developers are riding the name of civilization, and not producing quality product. The main issue here is the AI simply has no desire to allow gameplay. Your options (even on the most simple difficulty) are to choose one of 3 “paths” to victory, or schools of thought. I guarantee you that whichever you choose will frustrate the ai to the point they attack you even from a friendly status. If this were not enough, the aliens (cool concept, garbage delivery) are a wildcard who will overpower and attack you at any chance. Do NOT compare them to barbarians, as these aliens are strategic, have hordes of units, and will send siege weaponry to destroy your outposts and cities.
It is possible to pursue harmony with the aliens, thus making them a small amount more docile, but they will still attack workers, trade routes, ships, explorers, and outpost vehicles, thus crippling your economic pursuits.
Again, stick with Civ 5, and if you need to invest money in more civ, buy some expansion or DLC.
DO NOT BUY THIS GAME.