I thought Culdcept Saga was a great concept. I've loved trading card games since I was a kid, so it seemed like a solid purchase. What irked me about the game, though, was that matches against the computer can literally last for hours, with luck being the deciding factor in whether you win or not. Playing the same level for three hours, only to wind up losing and having to replay it again for another three hours is a serious test of patience. Receiving a few new cards when you lose takes away the sting a little, but the chances of you receiving anything useful are pretty slim.
Still, collecting the various cards is fun, and the basic Monopoly mechanic is solid. If Culdcept could somehow be streamlined, I could see it becoming a cult franchise of Disgaea-ian proportions.