Features:
Tech tree wont progress after Ancient age (so you wont reach other Eras). Also, several adjustment have been made to the tree to transfert fundamental features that would have been locked otherwise.
Dates increment have been adjusted so that when you are near the end of Ancient age, the date will increment much slower since its the final age (like modern age in normal games).
If 'Time' Victory has been selected, then after the 1500 turn, the date will fit perfectly with the historical end of the Ancient Age (Around 600 BC).
AI Civilizations choices have been restricted to civilization that have their unique unit in Ancient Age or fit in historically, allowing much more diversity for Warfare with unique units fighting each other. So when an AI is set on random, or when you dont go through advanced setup, Ai will always pick a civ that fit this era. No civ restriction is applied to the player, but i strongly recommend picking a civilization that fit in this era
All of the 'diplomacy' options that were after ancient age have been regrouped into a Tech Called 'Diplomacy' that was incorporated into the Ancient age tech tree, so you can do research agreement, Defense Pact and Open borders in Ancient age.
Technology costs have been adjusted to a viable scale for Ancient Era.
Agriculture must be researched at the start of the game. Agriculture also enable cities to convert their production to gold and science earlier when they have nothing left to build to prevent a city to be forced to produce millitary units when you dont want to.
Accessibility to 'Patronage' and 'Piety' policies in the Ancient age.
'Sea' tech tree has been altered with Embarkation available a earlier and Harbors transfered to the end of Ancient age tree to allow Sea trade route and naval warfare and embarkation.
Also, an additional Sea tech have been added at the start of the Tree: Fishing, to balance the Harbor and Embark changes.
the Technology 'Sailing' Now allow 2 Ship type (melee/ranged) to be built instead of just Trireme. (see below)
A custom unit has been added to Ancient Age Naval: The Battle Galley (Naval Melee). Trireme have returned to Naval Ranged, making Naval Melee and Ranged possible at Ancient age. (The custom Icons of diferent Size are made by JBAR81 and used with his permission. The same apply for the 'Fishing' Technology.)
All Naval and embarqued unit are allowed to cross ocean with the 'Sailing' tech (ancient age) instead of Astronomy, so you can still play islands map.
Unfortunatly, with current state of the game, it seem that Espionage cant be enabled sooner than Classical Era due to some game mechanic wich require a triggered age change for espionage to take effect. Therefore there is no espionage in Ancient Era. On the brigth side, due to technology cost changes made by this mod, tech stealing would be an unbalanced feature in the current Ancient Era setup anyway.
Since the Ancient Era was missing a lot of fundamental feature from classical age, several buildings were borrowed from the early-classical age and transferred in Ancient Age, in order to make this era viable for an Entire game:
Colosseum have been transfered to Ancient Era (Masonry) to deal with the lack of happiness source.
Courthouse have been transfered to Ancient Era (Writing) to deal with the lack of occupied city management.
Temple have been transfered to Ancient Era (Calendar) to deal with the lack of faith source wich diminished the Religion mechanic in an era where it is important.
Market have been transfered to Ancient Era (Trapping) to deal with the lack of Gold source wich caused a lot of problems vs unit maintenance and also to enable great merchant for this age.
Early-classical age Wonders have been transfered to Ancient Era to offer a larger choice of wonder and prevent every player to race the same few wonders available.
Bridge building have been transfered to Ancient Era (The Wheel) to prevent cities near rivers from beeing isolated forever.
Regarding cultural victories:
BNW users: Writing guilds have been transfered to 'Writing' tech from Ancient era, and the library now have a great writing work slot. This new culture source from specialist and great work act as as cultural offense and defense for this age.
G&K users: With Patronage and Piety enabled, you can finish your 5th policy tree for a classic cultural victory.
2 additional trade routes have been added to this era, One after researching 'Writing' and one after researching 'Diplomacy'. Also, 'Sailing' now extend the range of sea trades routes instead of 'Compass'. (Brave New World Users)
Caravansary have been transfered to Ancient Era (Trapping) to prevent land trade routes from being limited to few neighbors. (Brave New World Users)
The Future Tech concept has been renamed to 'Enlightenment' and transfered to Ancient age. A repeating technology that will increase your score and give +1 Culture and +1 Gold in your Capital each time it is research