TL/DR: Mix of RTS and Total war that actually works. Also the frequent crashes many reviews mention(I had to set autosave to 5 minutes to avoid going insane) have been fixed in late October 2014, so consider this in your purchase evaluation.(!)
Hegemony Rome: the Rise of Caesar is the Successor of Hegemony Gold: Wars of Ancient Greece which itself is sort of an Upgrade of Hegemony: Phillip of Macedon. All three Titles basically work the same so If you want to test the Game(or one of it's predecessors) any one of them(or a demo) will give you quite a good impression of what's going on.
What's good about this game?
1.) ... wait, you've read(or will read) other shorter/longer reviews, you saw the Trailer, you maybe even played Hegemony Gold. So I'm just going to skip this and go right to the bad things and you go figure out why I spent 100 Hours(jeez) on this game despite the bad points below, eventho I have like 200 other games in my steam account and a job that earns me enough money to buy said games ;)
So what's bad?
1.) Unit variety. Gauls/Britons/Germans all have the same old: Skirmisher(guys with swords), Slinger, Javelineer, Spearman and Cavalry. Gauls also get Archers, Romans only get Legionaries(strongest unit). Some subfactions get some statbonuses but most factions are essencially the same. I liked the variation in Heg. Gold, where Macedon, Persia, Athens, Illyria, Sparta, Nomads, Thracians and gerneric Greeks all had different unit-sets. They are however working on this and enabeling modding, so I'm optimistic.
2.) The AI, while not particualry stupid*, has significant limits pertaining to it's inability to grasp the game, it does not train veterans, it builds buildings seemingly at random, it does not manage it's food supply properly etc. on the other hand this makes taking enemy cities less time consuming^^.
3.) The forum is dead. If you got a problem, just ask here on steam, it's more likely to attract the devs, or other players for that matter.
4.) In the Campaign you command Kaisars Gallic Legions. A common quest reward are extra Legionary Cohor... Brigades. As you play a special Campaign faction(and not the regular Sandbox Romans) you cannot train them yourself, in turn you cannot disband them, sounds ok sofar. However, to replenish these troops(and your Uber Archer and Slingerunits) you need Roman Population. Now where would you find that? In roman cities. Now guess how many roman cities there are in Belgiu... Belgia. One. An average city can sustain 2-4 Brigades. In essence, unless you only use low morale Gallic troops you are going to spend most of your time waiting for your Capital to recover it's pop. yeesh. Having "culturechange" as a rare Questreward as in Heg. Gold would have prevented this.
5.) Workers/slaves cannot carry Food. Players of Heg. Gold will know why this is a bad thing, you essencially need to plonk down expensive camps everywhere so your troops don't die of starvation during a siege. That, or you upgrade your troops carry capactiy instead of Attack/Morale/Hitpoints/LOS/men per unit, and who wants that?
6.) the Campaign ends with good old Cheese-R explaining his righteous struggle against the Senate and then whining a bit about his death. Something I find quite a remarkable thing to do for a corpse. Then again I find most non-rotting-related things quite remarkable if done by dead people. Also with the (horrible) intro movie showing him lead his legions over the Rubicon I would have at least expected a cliffhanger hinting to a sequel where he fights against the Senate, that or an optimistic but mysterious ending that incites young people to look up what happend to him on wikipedia just to discover his grim fate, that would have been neat, and cheaper.
*it's actually pretty mean :(