By the way, this game is as addictive as any Civ game. I played until 3 last night (or this morning, take your pick). As Songhai, I've conquered almost all of the known world. I have Rome crushed without her capitol. The only place left I have to take is Greece (which has a bit larger of an army, but I have the tech superiority, plus I only need to take Athens). I tried a quick naval invasion last night and found out that, without a navy, an amphibious landing doesn't go so well. Decided to break my rule and reload to the pre-war state. I'll give it another shot when I get some free time.
Note: Songhai's ability is fun, but it has diminishing returns. Since you can't raze city-states, any gold you get from them is off-set by the unhappiness you collect. Also, I have a love-hate relationship with City-States. I think I have 6 or so allies. The rest I'm at war with because they think I'm a bloodthirsty despot that picks on the weak. Of course, I am a bloodthirsty despot, but I've at least been good to my friends. My first war was because China asked me to declare war. Another was because Rome attacked my allied city-state (for the second time and Augustus appeared to taunt me about it). The only one I attacked blatantly was China and that's because they stopped trusting me after I encroached on their sphere of influence and killed their city-states.