- For the original game which this boss fight references, see Dr. Robotnik's Mean Bean Machine.
The Mean Bean Machine is the second major boss of Sonic Mania, encountered at the end of Chemical Plant Zone Act 2.
This boss takes a radically different approach than other bosses in the game. Instead of fighting Dr. Eggman or one of his goons in a machine, you're going head-to-head with him in a match of Dr. Robotnik's Mean Bean Machine!
The boss begins as soon as the player falls into the game area, losing any active super form in the process. The standard rules of Puyo Puyo apply here - the play area is a 6 x 12 grid. Various colors of Puyos will fall into the play area, and the player must place four identically-colored Puyos next to each other, causing them to disappear. Chain reactions will cause Garbage Puyos to fall onto the opponent's play area, which can only be cleared if an adjacent set of Puyos is cleared. A player loses when enough Puyos in the third column from the left pile up to the top of the play area, causing the loss of a life. The player must either last long enough until Eggman's play area is filled, or send enough garbage to Eggman's side and cause it to fill. As the rules here are the same as in the original Puyo Puyo/Dr. Robotnik's Mean Bean Machine, offsetting and counterattacking are not possible, and the player cannot get a bonus for an "All Clear". Fortunately, Eggman has weak player AI for this boss, so he shouldn't be difficult for most players to beat.
If the player collects 21 medals from the Bonus Stages, they will unlock "Mean Bean", which is a minigame based on this boss fight where the player plays a best-of-3 match against the computer or another player.