Well...essentially its a fantasy strategy wargame that draws upon mythology from all around the world. This makes it a very, very original fantasy game.
Play the demo but follow the walkthru or you will be confused!
Actually, I did feel that totalwar had a similar 'feel' to it. The total war games emphasize the tactical combat though while dominions is really about the strategic level. I'm very fond of both... I'd love to see dominions-world battles using the total war battle engine, but I don't think we can expect that even in doms4!
Except one major factor with regard to Total War. This is PBEM capable. And that makes ALL the difference. AND the developers did it right. Instead of each nation taking sequential turns, they take simultaneous turns.