There are a few elements that make it resemble to Civilization, like cities, boundaries, improvements, bonus resources, wonders, everything is however blended to the needs of an RTS, so it is hard to make a paragon with Civ, even if the two games share *some* similaritities.
So RoN is a warfare oriented RTS, with a nice economical system. And yes, it is more accurate to judge RoN more similar to Age of Empires rather than Civilization, although the former doesn't share the 'epic' scale view that both RoN and Civ have. Like the fact you could easily build up a huge-looking army and you could watch your tiny and numerous men marching in compactness, everything made you feel you were commanding a nation, or an empire, not a simple tribe or a faction 'of the entire'.