This game fucking rules! I know a lot of people hate the PC port of the game, and I agree the port could have been so much better than it is. But still the game rocks! It's challenging, but I think that's what everyone loves about the game. There's that emotional high when you finally defeat that boss that's been kicking your ass hundreds of times.
The only thing that I don't really like about the game is the whole invading aspect. It would be cool if you could have the option if you want to PVP or not (and not being human isn't an option if you want to summon NPC's).