Ah, I saw that they've got out of beta (or whatever they call it) few weeks ago. It is quite interesting game, truth to be told.
If I remember correctly on their site people can play a bit cut down version which has unlockable things inside - if you donate (a class or two? more place in chest for another characters... or something like that) or just buy everything on Desura, right?
I've gone a bit in earlier versions... Like I've got this !SPOILER! fancy house under water, which really looks nice and gives people a place to return !SPOILER!
So yeah. As long as they keep adding stuff (and I think they were talking about adding more campaigns) it's well worth 9 euro.