LoA at first was a game that I thought would just be one huge virus! I would like to announce that I have received no viruses since I was talked into signing up for it with my girlfriend to play. Now, if you are looking for an action RPG where your reaction times greatly impact how fights turn out, I'm sorry to say, but this isn't one of those games. I think of it as more of a strategy RPG. You level up your character and recruit heroes into your party to help you fight. You can have any number of the many heroes in the game, but depending on what level you are, you can only bring a limited amount of them into fights with you.
Then there are also the namesakes of the game, the angels. Pretty much for awhile you only bring one angel in to battle with you, but that doesn't keep the other angels from being useful! They each have different blessings that you can activate for some time in exchange for points that you get just for clicking a button to worship each angel daily. Finally when you get to a high enough level, you get to have each member of your party being empowered by a different angel, so working on leveling up all the angels will be worth it as opposed to just one.
As with most RPGs, there is equipment. Here you spend gold to enhance it in the forge and also make higher level equipment with items that you collect from dungeons and other sources of materials. There is also a gem socketing feature to add more stats to your equipment. Now, I know in many other games either you just simply can not get an item back out of the sockets, you need to destroy the item itself in order to have a chance to get the socketed gem back, or you need to spend money to get them out. In this game, you just click on the socket and it's out! You combine gems of the same type and level to get higher level ones of the same type and can exchange one type for another type of the same level.
Now all of this can be done without spending a single dime on the game, but there is a cash shop which helps you progress through the game and there are items that act as different clothing skins as well. These skins give buffs, but you can get the same types of items elsewhere in the game. For example, there are right now 11 special mount skins that you can get each with it's own different skills that can activate when you use your special skills. Only two of these can be found in the cash shop. The other 9 can be earned in game by doing a variety of things. Most of the time these different things are events that last a couple days, some are just for earning these different skins. For example right now there is a 'Sky Archer' outfit that you can earn by doing a variety of tasks each day. Most of these tasks can be done without spending a dime. The ones that do are just ones like "Buy Diamonds" or "Spend Any Amount of Diamonds on Anything" to get a percentage of the costume shards. Everything else is just asking you to complete some daily things that you should be trying to do anyways for more experience or warsouls (like skillpoints).
Next comes a very good reason why I have met a few couples who like the game. You can get married on the game and it actually makes you stronger. You can do a variety of nice things for other people like tend their gardens, or just party up with them for some of the daily things like team dungeons and you earn intimacy with them. Once you have enough, you have the option to get married, here is the drawback though. Atleast right now there is no same-sex marriage. So if you and your significant other want to play together, I hope that one of you don't mind being a male and the other a female. There is a cash-shop item that changes your gender if you messed up in character creation and made the wrong gender.
Also there are guilds in this game, and every four days your guild has a chance to compete against all the other guilds on your server to earn some free daily items until the next little tournament. And every other day you also have a sort of defend event where you fight back NPCs from attacking a statue. And those aren't the only things you can do with your guild. You can host feasts with your guild and unlock bosses to fight and earn money from with your guild throughout the day, so don't worry about if you play with a lot of your friends that you will only be able to really do one huge group event every night, except for none every four days.
There are things like totems and dragons that enhance your party, but I have not reached that point in the game so I won't write anything about that. Overall the experience is great, but I have someone to enjoy it with in person, so that may or may not make my experience different than yours, but it is free to try and you don't need to spend a dime on it if you don't want to, but it may be worth it if you enjoy it, if at the very least to support a game you play.