Legends of Aria is being toted as the spiritual successor to Ultima Online. If you aren't familiar with Ultima it's a very old MMORPG. It was extremely popular and is considered pretty hardcore for today's standards. Nowadays MMOS hold you hand through everything you do. Need a group they will find you one. Need an in game tutorial for how to do anything there it is. Game too complex? Remove all complexity. Aria doesn't hold your hand and it's fantastic.
As of early access very little is documented, and what is known is most horded by guilds or players trying to gain a competitive advantage. You learn by doing and talking to others in game. With no way to whisper someone you have to either be in the same guild,party, or location with them. That means you're stuck using /say to strangers. The very same stranger that might kill you and take all of your loot. Oh yeah, did I mention it's full loot PvP?
Not a big fan of PvP? Slight problem as most of the world has PvP being enabled. The good news is killing people on sight has some negative things to it. It will cause you to red when you get low karma. Once they go red they can't use most towns and guards will kill them on sight. It makes traveling difficult. They can also be attacked on sight and you won't be penalized. Red players will also kill each other for the loot so they have more people trying to kill them then you do trying to kill you. The world is pretty massive so bumping into reds right now is relatively rare, but don't take stuff you don't want to risk out!
The crafting system is pretty shallow at the moment, but the framework is amazing! You can't put stuff on the auction house because there isn't one. You have to ask in chat if anyone wants to buy it or you need to buy some land and plop your player run shop down on it. Once you get going you can build a house to store more valuable stuff between your characters. Hopefully they add some more interesting stats to equipment, as of right now it's mostly plus defense, damage or accuracy.
The skill system in the game is different than what move MMO veterns today are use to. You can have 600 skill points total. Each skill maxes out at 100. This means you can only have 6 skills maxed which means you need to plan what you want on each character. This includes combat, gathering, and crafting so make sure you map out what you want.
The game doesn't do instancing either. If you want to go kill a big dragon you're gonna have to compete for it. That either means do more damage than the other players or you need to kill them all. After all if you kill them all that's just more loot for you. There are also dungeons to explore but once again instancing isn't going to save you...
The game is very rough right now. I'd say it's only got the framework up right now, and that framework is oddly fun. I'm a few days in with play time and I am loving it, but if you need a polished finished game then it's not ready. Maybe check back in January 2019 to see where it is when it launches on steam. Right now the only way to buy it is from the official site or a few retailers.
Hopefully you decide to give the game a chance. I plan to do some more tutorials and maybe videos to help with some documentation, but I might just get too carried away playing the game.