I just finished my first game as the Byzantines on regent. A really great game with the right medieval feeling. Quite easy too, but I should have played at least 1 difficulty level higher

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I don't know if you're going to make a new patch, but here's a few comments. I only played as the Byzantines, so it's going to be mostly about issues affecting them.
1) It seems that Turkish cities are auto-razed when they are size 1 because they don't start with any culture. Quite a pain everytime that I autorazed one to manually create a new settler using save game editors. Otherwise, the entire turkish peninsula and Persia would have been empty.
2) I initially restarted the game when I failed my first rush against Bulgaria. I didn't realized you had preplaced a wall in their closest city. It's an obstable, but it doesn't prevent an early archer rush. Same thing will all small civs (Serbia, Venice, Portugal,...). They usually don't stand a chance unless they backstab another AI.
3) Serbia's unique wonder is a tad overpowered. Free temples in all cities is okay in a three cities kingdom, but kinda freaky in a 200+ cities empire

. Every conquered city had a free culture and free happy face from the start. Can it be transformed into a small wonder?
4) What's up with the Aegan sailor? Is it a flavor unit or a Unique Disadvantage? Its only difference with the normal Man-at-arm is its higher cost. Honestly, when I compare a 4/2 infantry unit with a 50 shield cost against a 4/3 cavalry unit with a 60 shield cost (cataphract), I don't bother building the first. My entire army was centered on the cataphract and later on the pronoiar because the only offensive infantry unit the Byzantine can build is too costly and becomes obsolete with the coming of the late knight.
5) I really appreciated the vassal system. However, I felt that the empire gov might have too many vassal. In my game, I rarely saw a city with more than 4 shield lost due to corruption. Eight small wonders adding to your optimal number of cities+communal corruption rank+free town hall in all cities (Magna Carta wonder) = money whore. In fact, all the other AI adopted it except when they were down to 2-3 cities. They then went into City-state gov.
6) If you are Byzantium, you're the only one allowed spy missions. It's really a huge advantage when you have a large treasury. For example, I have 32000 gold running 500-1000 gpt and everyone is in awe of my culture. Every time a city gets captured, I run a couple of propaganda mission until the city flips. Sure, I did spend 11 X 512 gold on Barcelona until it flipped, but I was unlucky that time. Beside, it didn't really hurt my treasury. That's how I conquered all of Southern France and the spanish coast. I ally with a strong player against a weak one, he takes their city, I flip them and wage war on another front. If the AI could have espionnage in the Late Middle Age period, that would still leave an entire age for Byzantium to play mischief.
7) Small mistake in the pedia. It isn't written that Byzantium can't build Hospitalleers and Templar Knights even if it has the Holy Land ressource.
8) In the pedia description of the Sipahi, it says its a flavor unit for eastern civs. It seems that doesn't include Byzantium as I only got access to the Late Knight. Is that correct?
9) I would give a small wonder to Kievan Rus, Vladimir-Suzdal and Tatar that produces a settler every X turn. Russia will then eventually fill up especially if some crazy AI goes on razing rampage.
10) I was a bit surprized by the Renaissance Age. No new building except the artist guild which is a replacement for the tournament builsing. If you do a new patch, I suggest looking into ways of making 3-4 new building available in the last age. Perhaps a replacement for the caravanserai which expires with the New World tech. And a foundry which auto-produce cannons. It would make that age something more than just wonder grabbing.
Overrall, I really liked the mod

. I won a VP victory because I was tired of waging wars. I could have easily reached the domination victory had I been more agressive. Next game, I'll play an european civ to wage a crusade!
Here's a funny SS of the Almoravids thinking that multiple radar gives multiple bonuses. hehe, silly AI