Plain fun, addictive and most of all, very good developers.
New champions are added every two weeks together with patches which further balance the game. Although there is room for more balancing, the game is already balanced enough and those who comment on balancing issues most of the time are the ones who cannot counter any champion.
As regards community, LoL has a nice one yet there are those who really disrupt the whole gameplay. These are now being eliminated by the Tribunal which is a way of letting the community itself decide which players should be punished (find out more at www.leagueoflegends.com).
In this short review, I'm not going to tell you what the game consists of. I just wanted to do this review so those who check reviews may become more eager to try this game out. After all, trying a free game is worth it. Altough it is free there are things which you can buy with real money but these are cosmetics and don't affect the gameplay in any way. This is why it's a good game.
One thing which is nice is that when compared to other MobAs, LoL is all about innovation. New playstyles and champions are added constantly and new game mechanics are abundant. These game mechanics further improve this game and allow MobA games to elaborate.
Most of all though is the company itself, Riot, which not only constantly improves the game but most importantly listens to the community. This is a big deal because other companies might not listen to the community. Some improvements have been made due to complaints from the community which the developers take note of.
The graphics might seem to cartoony and if you're used to HoN's graphics you might find LoL's poor. However you will sosn get used to them and sometime soon, the company has declared that there is going to be a graphics update and all the graphics are going to be renovated.
To conclude, this is a game worth playing whether you are a hardcore MobA player or just a new gamer to these types of games.