Also interested. The game is hilarious. Are you still working on an update?
I would personally like different forfeits for the losing side, though (either you or CPU). Spanking is funny, but you could make it more humiliating, like jumping up and down, twirling, or even more explicit, like masturbation or whatever. Perhaps more tailored to the characters and their fears.
To make it more challenging, you could consider making the player restart the game completely in the unlock mode instead of just replaying against the same opponent, or make the boss more of a tougher challenge somehow. The boss is currently the least fun opponent. Maybe a slightly higher difficulty overall wouldn't hurt.