I especially enjoy levels with a variety of different environments, ---- so that your not just stuck in one cave or factory for the entire time, thus the ruins setup where you can go from outside to lost city type backgrounds to caves is a favourite environment of mine.
It's also really nice to see a remake of a different level of T2, --- sinse currently it seems that the factory stages get all the love.
My only real problem was that the hole level seemed a trifle too easy. Far too many power squares and one ups, and not as many enemies as their might've been.
Of course, it might just be that I've played two many harder levels ;D.