What 'Elements' -make a great level?

[tensorpudding]

I guess a rule of thumb might be to put monster dodging and luck-based elements nearer to the beginning, put sokobans and boring repetitive moving-things puzzles nearer to the end, and generally have a decreasing difficulty curve through the level. But often I found myself enjoying levels with difficult puzzles all the way through, despite how many times I had to repeat the beginning. Some puzzles are great because you have an epiphany that makes the rest of the level easy, but until then you try many things without success, wracking your brain for minutes or hours or maybe days. The truly best puzzles can do this more than once.

If the puzzle is really good, you'll probably forgive a little bit of tedium in the beginning (but only after you beat it)