I have beaten Age of Empires III Complete Edition.
This might not be as good as AoE II, but it surely is epic as hell. The campaigns are way better, although much shorter. The units are very interesting and well-balanced. The difficulty is ok, but maybe The War Chiefs was the hardest of the bunch (nothing that I don't like though!).
The only thing that left me a bit unsure were the ''stealth'' missions. They were ok, but they make no sense. And the acting, with the exception of the narrative and the very last campaign, isn't that great.
Overall, this is a fine game. 4/5 would play again. Maybe I will download some custom campaigns, one day.