I might have found an unintended solution to the last level, which I finished without using any of the bushes on the right-hand side of the map. Don't want to spoil anything, but I've got a screenshot if that's helpful :)
Only level 36 to go! But I'm totally stumped on that one..
Thanks for spotting that, I think I've found your solution and I've updated the game with an easy fix, let me know if it there's something else I've missed.