Well it's the same kind of dungeon RPG as Diablo, but it's got enough differences to be distinct. The currency system, the spells attached to gems (with a complex support system), not to mention the in depth skill tree, pvp, different leagues, races, etc. It's a fun game for theory crafters, which is something I enjoy.
I played for a couple of months off and on. Was a fun game and the price was right! Had a falling out with it but I do that with a lot of games and I go back to them off and on. Good fun to just kill some time.