Thanks for the info. I probably won't even try them. You see, I absolutely hate hand-to-hand combat style games. (In fact, I gave up on the demo early on because I was turned off by the combat. Fortunately I listened to people here and played the demo further and realized it was a much deeper game than that.) Anyway I just don't have any desire to play those challenge rooms. The predator ones on the other hand, l could have some fun with.