Ascendancy was the most innovative space colonization strategy in its days and still is!
In general the game has quite a collection of species to choose from and each has its own special ability that helps it progress faster in some ways. Each planet you own adds to the cumulative research power to speed up your research while industrial muscle remains individual to each planet so building ships for instance is preferred to massively industrialized planets. The main goal either kill the other races or form an alliance with them (or some of them and destroy the rest)
Overall the game is nice and fun to play and research the entire research tree but it almost always doesn’t come to the need of discovering everything since the game is simply too easy. the computer controlled rivals doesn’t pose much of a threat in strategic planning and usually always technologically lagging behind you so the only two ways to make it harder is either to make more opponent races (maximum of 9 I think) which isn’t that much better or you can download the "Antagonizer" which is more or less a fix for the stupidity of the enemy but instead it makes it almost impossibly strong in terms of thinking power so unless you are very good in this game you will find yourself loosing pretty quickly.
Nevertheless it is an original piece of work. The creating company (Logic Factory) also made another original not-so-strategy game called "The Tone Rebellion" with more mysticism in the concept so if you liked Ascendancy you most likely like this too.