I actually really enjoy this game despite it being VERY hard at times and a little buggy.
The game can go from being easy as pie in one moment, to almost impossible at the next but I find that keeps it exciting.
Rather than being able to rush through the game, you have to think, pace yourself and plan which many games now don't seem to do.
There are different game modes too, depending on how you want to play and the random generation make the game highly replayable.
My few gripes are firstly - the mulitplayer. There was such potential for it and so many ways it could be handled and instead it's ended up being a 1 v 1 type thing.
Also, the game has it's fair share of bugs, which I found bearable (the game autosaves before each node) but many people seem to be pretty annoyed by them so if you're looking for a bug-free experiecne this may not be the game for you (but neither will Skyrim or Fallout).
But for the price of the game you cannot complain. I got my money worth at least three times over (I own it on Desura too).
If you enjoy randomly generated games that can get hard but are incredibly addictive then this is for you.