The Fiend's Cauldron from Kid Icarus Uprising. At the start of a stage, you have to wager currency on how high of a difficulty you want to attempt, on a sliding scale from 0.0 to 9.0. Higher difficulties cost more to play, and if you fail, you lose your bet and the difficulty drops if you choose Continue. It's an interesting system for how it forces you to check your ego and self-evaluate just how much you think you can handle.