Wow, this is a tough one. So far, I've had two aborted games, and one lost one. Guess I won't be submitting any official entry for this one.
My first thought was: top military, let's tribute! Indeed I could, but you still need some military next to the city state. I did not get a spearman upgrade for my first attempt, so I built a warrior, bought another one, and finally I could tribute, but only two city states for a total of some 110 gold. In the meantime, I was being severely crippled by the unit limit. It had been mentioned in the announcement thread, but I had not really taken it to heart, so I was suffering a 30% production penalty while building my first settler. I felt the game was going nowhere, so I restarted.
For my second attempt, I wanted to make some early use of the missiles, so I planted a city near Tenochtitlan, and tried to capture the city. I could: two missile shots and then capture the city, making sure I had an entry without getting zone-of-controlled. Of course, then I hold Tenochtitlan, but it's surrounded by 10 Aztec units. I sold the city to Shaka, hoping to retake it later, which I eventually did (spending another two missiles because I could not spare units, fighting a preventive war against Attila), but the problem was not solved. Monty was down but not out, with three cities surrounding his capital. When he declared war and took his city back (I paid for a war against Harald, but their hearts were not in it and they made peace), I abandoned my second attempt as well. I was not dead yet, and looked like I was even getting Petra, but I had spent 4 of my missiles with little to show for it. I tend not to enjoy my games when they are very slow, so I decided to try once more.
Before my third attempt I asked myself: what good do these missiles actually do? Initially, they are a hindrance besides the tribute potential: at 3-pop you may have your starting warrior and two scouts, but anything above that and you get a major production penalty. I considered selling them, but they only net 37 a piece. So I concluded they should be used against Attila to aid with a war against him, and then later worry about the rest of the map. Unfortunately, my third attempt did not work out that way. Armed with map knowledge, I toured the city states with my spearman (new random seed looks to be off, so
if you walk northeast you will get an upgrade ruin turn 2 or so), collected the tribute which I used to buy an archer and a war elephant, and set about getting my sim going in preparation for war. In total I had built two settlers, a shrine, a granary, a caravan and most of a watermill when he attacked. I had expected the missiles could be used to ward off an attack, but 5 'free kills' did not save me when he brought an army of 20 (also my spearman and archer were out of position, but they would not have been sufficient to defend, either. Delhi captured, turn 63.
I might have a final attempt, but I will need to change my tack (probably declare war on him so he does not send a big army at once), or be lucky that he simply does not attack.