Tis a free 'MMO' available through Perfect World. It's not really an MMO because while you may have many playing on a server, they divide the players into 'channels' which means you'll not often see more than 4 other people. However this is good because there are only 4 different characters to play as (so you don't see a group of Angelas sitting around the entrance to the dungeons).
It plays like a hack slash in instance dungeons that are separated into sections that you must slay monsters in before proceeding to the next section (although sometimes there are multiple paths).
You can play solo or as a party. I managed to play up to level 22 (out of 45?) with the game posing no real challenge, however I feel I'm gonna have to buddy up with a few people to get decent ratings in the dungeons (the game gives you a rating at the end of each dungeon which determines how much xp you get).