The usage of simple sporadic groups adds a new dimension to any puzzle.
Oskar's new creation may be somehow related to the Think-a-dot puzzle by ESR,
but they can not be compared in terms of difficulty. Oskar's puzzle also uses
some extremely interesting "avalanche" technique, making it even more desirable.
As for Pachinko, the puzzle was presented at the IPP, but (as I had stated)
there were so many things I had to do, I regret I didn't try it at all.
Oh well, I am sure I will see them again one day!