First Genius level using the Desert style!
This level was originally a Sneaky level, then I found a more complex solution, blocked out the old one by removing some skills and upping the requirement, and popped it into Cunning. Then I found a solution without touching the ground in the middle (with a couple of skills added), so I made this the solution, added the water, and put this level in its current home, Genius 12.
Genius 12 - "King of the Sandcastle"
100 Lemmings, requires 97%
Release rate 20
Time limit 4 minutes
3 climbers, 0 floaters, 1 bomber, 3 blockers, 6 builders, 13 bashers, 5 miners, 10 diggers
It's quite easy to tell what trick this level uses; exactly where to do it and how to set it up is another matter.
EDIT: Not due to the above level, but now only 25 levels to go! =D The downside being it's mostly Cunning/Genius levels I have to come up with (indeed, I've been reluctant to fill the last few slots in the lower difficulties, so if I make a level that turns out too easy I can chuck it into one of those rather than it being a wasted effort - if they remain unfilled, it's very simple to throw together a Nice or Cheeky level, and Sneaky isn't too much harder to work with). My other concern is that I don't want the styles to become too unbalanced. I'm not aiming for 4 of each style per rank, or even 20 of each style altogether (perhaps more along the lines of "between 15 and 25 of each"), but I don't want a case like with crystal in the original game where barely any levels use it and those that are aren't overly notable. At the current point, Tree and Purple have 15 levels each, Psychedelic and Metal have 17 levels each, and Desert has 11 levels. Pretty good that Purple's completely caught up and Desert isn't far off, considering how much later those two (especially Desert) were made than the other three - and in desert's case, it didn't get an easy freebie in the form of a Floater Frenzy.
EDIT AGAIN: Just noting, the above shouldn't be taken to mean that the Nice/Cheeky/Sneaky levels are rejects from Cunning and Genius. While that is true of a few levels, the majority were intended to be low-rank levels from the earliest point at which there was any clear "intention" at all. In fact, the reverse is far more common (lower-rank levels getting bumped up when I reassess their difficutly or revise them to increase it) - you could say that a lot of the Cunning and Genius levels are rejects from the lower ranks. =P