I pity anyone who has to review, or god help them, write a guide for Terra Invicta, because doing it even semi-comprehensively would take longer than I expect to live.
This is a hugely ambitious game, covering something I've never seen before, with a scope that makes Europa Universalis seem limited. It is a complicated, huge, and ponderous alien invasion simulator that constantly threatens to drop the other boot on you the entire time. Anything you do could be the butterfly whose little wingflaps eventually result in the obliteration of the planet. It is not a game to be powered through, but to be played and contemplated exclusively for a solid month.
That is its central weakness. But I think it had to be this way. Its commitment to an idea is demanding, but if you can tolerate some issues with clarity and presentation, the payoff for meeting it is utterly unique.