I wrote a 3d rubiks cube slot machine for my old online casino. It scrambled the cube randomly 4 times and gave the player 60 seconds to solve it by twisting up to 3 times. Lots of weird quaternion math to handle the spinning and shift key twisting at the same time. All with simple geometry in Away3D / AS3.

The real hard part of designing that game was creating the payout structure. The game paid an equal amount for each "line" of 3 colors in a row on any face after the player made their third move. There was a progressive take and jackpot for a perfect solution. And I specifically wanted to target a zero house edge for the game, to reward the best problem solvers. So the question was, given 4 random twists off a perfect cube, what are the individual chances of getting 64, 63, 62...1 lines of sequential color given the best 3 spins from the initial random state, and then hiw to allocate the payout structure accordingly.

Probably a billion monte carlo runs and I had a pay table. It was lots of fun. I wish more gambling games rewarded skill that way.