I personally like how the singleplayer aspect of SoaSE has gone and where Demigod's is going. Very much like multiplayer matches, but with AI instead of humans. Of course I purchased these under the idea that that was how singleplayer was going to be. A campaign was not expected.
Now if you want to see a piss poor excuse for singleplayer with a massive multiplayer focus, see Dawn of War and Company of Heroes. Campaign was very easy, and the expansion packs just made the pathing and AI opponents mcuh, much worse. If it werent for AI mods, I'd never even play them; now I've heard it's gotten even worse in DoW2, but I'm not touching that (reasons off topic).
Now, if you are expecting a singleplayer experience like that in say... Mass Effect and GalCiv2, then run away! But if you are looking for what is essentially an incredably well done and organized (tournament) skirmish mode, then look no further.
This comming from someone who hates online play.... see following link for details, and a cool suggestion from me!
http://forums.demigodthegame.com/341129