The opening music is bliss, especially when you realise the words are the Lord's Prayer in Swahili and not some meaningless Lion-King rip-off as I first feared.

Swordsmaster, you probably know this but the key to taking a city is artillery-type units. First bombard the city to get the defenses to zero. Then throw 3-4 artillery units at it in suicide attacks to cause collateral damage on a bunch of the defenders. Then hit the town with your best assault troops. Other things being equal, you may lose 2-3 artillery doing so but you should not lose dozens. Choosing your promotions wisely will help (city raider is a no-brainer, but note the trick of upgrading pre-gunpowder units with it, as any newly recruited gunpowder units are ineligible for the promotion; I used to get collateral damage for my artillery but am now wondering about city raider to allow them to actually win).

Sieges can be tricky in the late period, when railways allow easy reinforcement and counter-attacks. That is a good feature, as it makes isolating a city crucial (think Leningrad).