I liked most puzzles. I just found it a bit strange that the untouch Killer didn't need the extra constraint. When I solved it afterwards I didn't use the untouch at all. I am not sure how the opening was supposed to work, but the way I did it, I had no use for the the untouch rule and after you get it going, thinking about the untouch rule would just be distracting when you can just work the cages.