I re-watched the trailer and paused in every part showing gameplay and learned the following things
- Ships and bombarding units have a bombarding strength.
- Promotions, Civ4 style, are back. (At 1:30, A musketman unit gets promoted and when the cursor mouses over it text appears that says choose promotions for this unit.)
- Like in Civ4, a chances chart will appear before a battle, but will more clearly show combat modifiers.
- In the beginning, during diplomacy with Egypt, the player is trading five horses. It could be that he is trading enough horses for five units.
- At :41, a bonus is shown called the "Flanking bonus"
- Bombarding units like catapults can attack two hexes away.
- A class of "Specialist buildings" is shown at 1:35. No idea what this is.
- Golden ages are back (says at top of screen for most of video)
- The information about battles and events at the top of the screen is back, seen after battles.
- Great Generals are in