Grimrock

So during one of the dreams, the evil cube mentions that his "people" built Grimrock, and that it was turned into a prison for him. Assuming he was telling the truth, what was it's purpose before? He also wonders why those controlling the dungeon just don't kill you outright, since it's well withing their power. Later, when you find Toorum's remains, he talks about how he thought that he knew the dungeon's rules but still got trapped, and that he could hear "them" whispering something out how he wasn't worthy. Does this mean that Grimrock is some sort of test to only let those powerful enough to kill the cube thing?

I can't be the only one who found the story somewhat interesting, can I?