Well, let's see now.. I've gotten 100% on rapture and the end now.. Started Cotton Alley maybe last night.. ? I'm at level 7 or 8 on the light world, haven't really played yet today, and I stopped at about lvl 2 or 3 on the dark world because I figured I could just finish the whole light and THEN the dark..
Skyscraper actually only took me maybe a half hour? An hour tops.
Death is Meat actually tortured me for a bit yesterday, if only for the fans in the final level.. Lord, how I hate levels with fans.. I would beat the first two levels with absolutely no problem only to quickly die on the final level, but I sort of figured out the figure-8 sort of movement you have to do before going from one fan to the other to safely cross to get the key and go back..
Now I think 7-7 has fans.. About to go and attempt this one, now. Wish me luck!