I'll start by saying this:
This is easily one of the best RPGs I've ever played. I don't think there's another game out there that captured my interest so quick. But that doesn't tell you much. Let me elaborate.
Age of Decadence is brutal. It's painful. It will kick you while you're down and do it again, and again, and again. Every situation you'll encounter in this game is either going to leave you in a life or death struggle or trying to piece together things you couldn't hope to understand, and that's a good thing. This is not like modern RPGs(i.e. the more recent incarnations of the Falllout Series, Elder Scrolls, Divinity, Underrail, etc) nor is it entirely like those of old(Fallout 1 & 2, Baldur's Gate, etc.). I am reminded of all, I see influences while playing it, but Decadence sticks out on its own. Again, I think it has to do with difficulty.
Decadence hands nothing to you: you pick your character background, assign some basic Stats, and then pick a few skills to upgrade. Character creation leaves you tied to what you make--A strongman swordsman with wind blowing through his ears will still be dumber than a bag of rocks by the end of the game, a persuasive talker who has no combat prowess will consistently get shredded within moments of entering combat. What you make is what you get.
To put it another way, Decadence does not put you in the shoes of the hero. You can die in the first fight very, very easily( I have, multiple times), and I'm sure you will as well. You are very much an everyman, someone thrown into a world that can and will exist with or without you. The only time you're ever going to be anyone of status('Hero', 'Chosen One', 'Scourge of Humanity', 'Demi-god', etc.) is by putting enough people down at your feet through hard-scrabble fights and barely coming through alive. You have to live a legendary life before you can become a legend yourself.
Thereagain, that's assuming you choose to fight at all. This isn't necessarily a combat oriented game--you can talk your way out of things, trick, cheat and steal your way to success--Decadence encourages you, in a way, to avoid messy solutions. In fact, it'll often get you farther in terms of understanding the game world, story, the politics of the world Iron Tower has created and the people and creatures living in it. It'll also leave you cursing yourself as misallocated skill points cost you the opportunity to read that dillapidated scroll in an ancient library, or pull off negotiations with a feuding noble, or figure out a way to talk your way through a horde of angry tribals who want to throw you into a pit with an abomination from ages beyond. It's not any easier, certainly, the life of a silver-tongued devil compared to a battle-scarred warrior.
Sounds rather difficult, right? For people who have some kind of enjoyment of punishment and pain?
This game will teach you to enjoy failure. Half the fun will be trying again, in dealing with the failure. There are moments, certainly, where things get to be a little ridiculous(I wasn't very happy when I had to trash my first character partway through) but once you get into the game, things move quick. Trying again isn't so bad after you know what to do, how to maximize your effectiveness in the playstyle you shoot for. And sometimes, you'll just have to reload and try again, and hope the rolls are kinder to you, that your hits land this time and that four-armed monstrosity you're fighting stops landing criticals every hit for the past twenty loads in a row.
Furthermore, it's very, very hard to make a decent jack-of-all-trades character, let alone an expert in everything. Honestly, it's hard to go purely for combat, or social skills, and so on. It takes some maneuvering to get your skills where you need them when you need them. More often than not, you'll be reloading or restarting entirely, trying to find out the best order to do things, the best way to spend your points, the best options to choose in each situation so you don't hit a brick wall later on, finding out you literally cannot progress past a certain point because of errors in character building.
Going off the jack of all trades, to fully experience the game, you(probably) will have to make multiple characters. At the moment, I've got a mercenary/warrior character with some light social skills and a character who is built entirely around understanding the ancient history of the gameworld(there is actually a skill for this in game, called "lore", and it's rather useful) as well as persuasion and the like. I'm probably going to have to make another one, and one more, and so on to really get the full picture. You will too, and probably will want to. Each character has a very different story, a very different interaction with the world: you'll need quite a few to get a good picture of it all.
Speaking of the world, the "bigger picture": This game has some serious writing behind it. It, quite simply, turns your expectation from a possibly predicatable RPG storyline to feeling like your reading a novel that's just setting the stage for an entire series. There's a huge meta-plot going on beyond the actions of your character--the story becomes as much about the world your exploring and its history as it does about your character's journey through it and it left me craving more. In fact, I made that lore-based character I mentioned earlier solely for the the purpose of digging deeper into the realm presented. Like the inhabitants of the world of Age of Decadence, I wanted to find out more about the fantastic world they lived in, what happened to it, and how exactly it got to where it is now.
At the time of writing this review, the game is still in early access, and we're waiting on a big update to wrap up the exisiting questlines, locations and so on. So, be aware you might not be able finish the game right yet if you buy this in early 2015. However, there is so much content you won't get bored while waiting. Best of all, you can(probably) use your previous saves in future updates--barring any serious scripting errors that might arise in the future with updates and so on, older saves seem to be pretty compatible with new versions of the game.
All in all, I am very happy with my purchase(I've owned this game four or five days and already have 30-40 hours in it) and I can't recommend it more. Well worth the price.
If you have any doubts, try the demo first. It's there and is a good representation of the gameplay. Also, try reading the forums and asking around if you're not sure--the community is very friendly, as are the developers.
Do you like difficult, challenging RPGs with great writing that encourage that force you to learn from your failed attempts and turns it into something enjoyable?
Then buy it.
Oh, one last thing: Save like a madman! You're going to die soon.