Showdown (also known as The Final Showdown in the manual of the 8-bit game, or just Final Showdown in said version in-game) is the fourth and final level of Sonic Spinball for the Mega Drive/Game Gear/Master System, coming after The Machine. As with other stages in this game, Sonic must bounce through the pinball-like level, acquiring Chaos Emeralds, which are in turn used to access the boss. In this stage, five Chaos emeralds must be found.
After Sonic destroyed the Veg-O-Machine in the previous stage, Robotnik detached his self-imaged spacecraft from the launch base at the top of Mt. Mobius, attempting to escape to the stars. Showdown takes place both in the sunset scaffolding of the rocket's launch pad, and inside the hovering star-ship itself. At the bottom of the level rests the magma-filled caldera of the mountain; missing the flippers means an instant fiery death.
The final boss, Robotnik's Ship is a located above part of the stage. As with all bosses in Sonic Spinball's, Robotnik on his ship has no means of harming Sonic directly; but it does have plenty of ways to throw the heroic hedgehog out of the boss area, sending him air surfing down, down, down towards the foot of the stage so you have to work your tedious way back up to the top.
While normally only Sonic is plummeting to probable doom all the way from space, this end sequence shows Robotnik falling with him. Sonic is rescued by Tails on the Tornado; however, Robotnik is left to tumble back into the crumbling maw of the Veg-O-Fortress, as Mt. Mobius collapses into the sea.
- This is the second of two levels in which the player can earn score multipliers by passing through a series of gates, each one with a light over it that turns yellow when that gate is passed through. Lighting all three increases the multiplier by one. However, this is reset whenever Sonic enters the ship.
- At the end of this level the player is awarded bonuses based on categories such as how many balls are still remaining (five million per ball or "life") as well as a Jackpot Bonus: the player receives ten million points for every Bonus Stage completed, including multiball stages. A 100% success rate here would result in a 70 million points bonus (three normal Bonus Stages plus four multiball rounds).