Final Frontier is an Accident mini-game in Sonic Shuffle. It can randomly occur by accident in Fourth Dimension Space.
This mini-game starts with everyone standing on a series of platforms that are being sucked into a black hole. More platforms come from the top while the ones on the bottom go away, so everyone must move around and jump to avoid falling. The centers of the platforms open up that either give a blast of fire that will make players lose Rings or shoot a small fountain of Rings or a Forcejewel. If a player falls off the platforms, they will drop back onto the center of the platforms and lose 5 Rings. Some of the platforms in the middle will also fall down, so players must watch out.
Whoever collects the most Rings by the time the clock runs out gets 20 bonus Rings; second gets 10, while third gets 5.
||Jump on the platforms and get the rings!
— Instruction displayed when the mini-game begins