Originally posted by Rhalius:

I play pretty casually, so far only with resource cheats enabled to just see what every faction has available and how they play to get a feel of the game.

I'm aware work on this one started later than Sparta, currently I do prefer Sparta due to all factions being able to put archers on walls, having more buildings, maps that allow for naval combat and a larger range of playable factions but I am very curious to see what new additions might come to this game over time before the official release.

I'll start with a bit of feedback specific to each faction, and then close off with a bit of more general feedback that can apply to all.

-Mongols.
They are pretty solid, them not having walls makes sense with their playstyle and ability to move camp. I like that Ghengis Kahn has a horse from the start, and would suggest more heroes if not all have a horse right away, they are very much THE cavalry faction after all.
It's why they certainly are a good candidate to have more than one kind of horse available at their stables, maybe even three while other factions could maybe only get two at most.
Could also be nice if every single one of their units can be put on a horse, even the workers though they can't work much from horseback, it would just help to escape or collect weapons from the battlefield.
For new buildings or units, maybe it could be something to have a building for different cultures they historically subjugated that can provide them with some units and equipment to train. Like the Chinese giving them some siege and a basic spear infantry unit.

-Byzantines.
They could really double down on being the defensive civ, I think all civs should be able to put archers on walls but the Byzantines could maybe also upgrade their gates with gatehouses that can pour boiling oil, have tower upgrades that allow siege weapons to be put there and maybe have some upgrade to make their walls stronger.
Furthermore maybe the Cathapract could become a separate unit trained from a special building just for them, having a lot of requirements but always arriving on an armoured horse. It's a bit odd to see a cataphract not on a horse, or an unarmoured one.
Their elite basic unit could maybe be a more late roman looking unit, could also add a bit more variation since their three basic units look more similar than of any other faction.

-Arabs.
As mentioned elsewhere, would be nice if they have horses available too. Maybe beautiful white arabian horses. Having the camel as well as a regular mount option already makes them unique, possibly they could also get armoured camels to double down on that.
Maybe they could get an assassin guild new building where they can recruit more than one kind of assassin, each working in a different way to keep opponents on their toes but always high damage units with low health.
One could be a saboteur that can use early grenades to deal a lot of damage to ships, siege equipment or buildings especially.
Another could be a fast moving stealthy agile woman with twin scimitars who is hard to hit with ranged attacks, deals a lot of damage to all enemies next to her but also has little health to survive long in melee.
Could also be an expert archer with poisoned arrows that deal damage over time and he has long range. He could have a slow rate of fire however.

-Russians.
I like their different defensive options, I like that they can expand their main building with attached buildings too and can put up a palisade in a circle around the town too.
I'd like to be able to put more than one gate in that palisade however, might also be nice if workers can also build a palisade wall elsewhere. The wall the main building can put up could maybe also be upgraded to allow soldiers to be put on it, while the workers can only build the simple palisade wall.
They could use another ranged weapon option as well, two is very little.
Perhaps more of their buildings could get an upgrade too since that seems to be sort of their thing.

-Crusaders.
They very much could use walls that allow for towers and archers, maybe they could have some nice siege options as well to conquer other walls since they are an invading force.
Currently the templar guardian looks very similar to the templar knight, perhaps they could look a bit more different to more easily tell them apart. A cape could maybe work for the guardian.
Might also be nice if the Teutonic Castle can be upgraded to have an attack and be more of a castle, and perhaps Richard Lionheart could be moved to the main building's heroes with them getting a Teutonic Grandmaster recruitable there in his place.
Maybe the Knight's Hospitaller could also become available with their own building that also heals nearby units and can train good healing priests as well as several knights. They could work a bit different from the Teutonic order, their knights could maybe regenerate health slowly.

That covers all the factions, I do hope more might be added over time to be more on par with Sparta.
I think the Turks and Hungary could be good additions to the game, allowing for a Vlad the Impaler campaign for Hungary and a campaign for the Turks conquering the Byzantines.
The Turks would have their sipahis and jannisaries, could maybe have some gunpowder units too.
Hungary could have romani witches and brigands in addition to a solid regular eastern european army. Perhaps they could choose between building a church or a pagan temple, one locking out the other and providing associated units.

Other possible factions I could see happening would be Spain and the Moors for a reconquista sort of campaign, Kingdom of Jerusalem, Poland and Venice are other plausible options I could see happening with a unique enough feel to them.


Now onto some general suggestions that could work all around:

-Siege workshop of sorts.
With all factions getting walls that can have archers on them, there can be more focus on siege warfare which fits the crusades. It would pretty much bring that building in from the Sparta game, with similar options and all unlockable research for siege weapons from the forge could be moved here.

-Market with trade.
Allies could trade something with each other, which can be resources but also a weapon or shield type you can create that your ally can't. The trade wagon will send shipments of those things for the ally to use, but enemies can intercept it and grab those weapons or resources for themselves.
Just needs some way to ensure markets can't be placed too close together to avoid exploits so there's always a danger of it being raided.

-Training yard.
Could maybe be something for some factions to improve their units experience for a price and it would take some time. The units would be shown using the training yard for a while.

-Bridge building.
Could maybe be an interesting way to cross rivers, maybe it could be at set spaces. I saw bridges on at least one map. Could be nice if those could be destroyed, but also rebuild by workers. Some maps could maybe start out with spots where you can build a bridge but not have it from the start. Only siege weapons could target and destroy bridges. Any units standing on the bridge when it's destroyed could be instantly killed, adding danger to the crossing.

Maybe I'll think of more in the future, but this is all I can think of for now.