Honestly, I'm only confused as to why completing the game nets a 15 point achievement. This game is brilliant, and pushes mental position a lot farther than a lot of books. In fact, just to solve the puzzles, you need to fully understand why the argument is invalid, and then use limited tools to prove exactly why. Granted, it could be a lot harder (such as, if you were /actually arguing/ with Kant), but the notions it puts forth are still pretty solid to begin with.
I only just found this series and have made my way through first, second, and prequel, but this is absolutely amazing!
Of course, seeing if there was a limit to the rooms was a little stupid. I got to (-250, 1) before realizing there was a point to things. Whoops. Absolutely bloody brilliant, though; a real delight!