I'll fix that thank you. Impossible puzzles shouldn't be possible.
Tested over million generations. Maybe it was caused by another bug. I'll investigateEDIT: Fixed the empty levels.
Another one: level 11 has 2 challenges, but it says 0/3 (or 3/3 when completeed)
one challenge gives you 1 crystal, the other one gives you 2 crystals :D
Ahh, I see!
