While I wait for my brain to recongeal, I'd like to offer my thanks too. For what it's worth, I found level 24 to be the toughest.
Yeah, 24 is probably the hardest one. Glad you enjoyed the game :)
yup, 24 is the only one I have left to solve and made me hugely appreciative of the level select option! Otherwise I managed to do things more or less chronologically, apart from 36, which succumbed before I'd gotten my head around 35.