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For the video game, see Dr. Robotnik's Mean Bean Machine or Dr. Robotnik's Mean Bean Machine (8-bit). For the object, see Mean Bean-Steaming Machine.

The Mean Bean Machine[note 1][1] is an object that appears in the Sonic the Hedgehog series. It is a contraption created by Dr. Eggman that forces its unfortunate victims to go up against the doctor in a puzzle game that utilizes Puyo. Losing a game in this machine has dangerous repercussions.

Concept and creation

In an interview with IGN, the leading developer of Sonic Mania Christian Whitehead explained that "the Mean Bean Machine boss was the most complex boss to create, since it was essentially a game within a game" and had to research the rules and replicate into Mania's engine. He described the boss's design as "a really dumb input generator" but with the assistance of programmer Hunter Bridges, they were able to create a robust gameplay experience of it and has featured a separate unlockable Mean Bean Machine mode. Whitehead did not expect Sonic Team to approve the Mean Bean Machine boss (since it was under a different license) but "[Sonic Team] thought it was funny" and helped to implement it.[1]



The Mean Bean Machine is a section embedded in the depths of the Chemical Plant Zone. The area is made up of gray metal with and yellow and black hazard stripes and pipes with blue Mega Mack flowing through them. On the left and right side of the section is a large tank with a pipe that drop Puyo into it. Also, in the middle of the section are two identical cabins with adjustable consoles and trap doors on the bottom that each lead into a pipe.

Features and traits

The Mean Bean Machine is based around a giant puzzle game which two constants can participate in at the same time. Each constant controls one of the machine's tanks. The machine itself drops slow-moving Puyo into its tanks which will only disappear when the Puyos are arranged in certain formations. While their respective tank's Puyos fall, the constants can control their trajectory from their console. If a constant's tank overflows, they will be dropped down into a dangerous pipe.


Sonic Mania

In Sonic Mania, when Sonic, Tails and Knuckles tried to exit the Chemical Plant Zone, they got dumped into the Mean Bean Machine, where Dr. Eggman challenged them to a puzzle game, having decided to defeat Sonic and co. with his intellect instead of brute force. However, Eggman's plan backfired when Sonic and co. outplayed him, causing Eggman's cabin to blow up and send the scientist plummeting down a pipe while the heroes escaped the Mean Bean Machine unharmed.

Sonic Mania Plus

In Sonic Mania Plus, the Mean Bean Machine was used by Dr. Eggman again when Sonic, Tails, Knuckles, Mighty and Ray got caught in the machine while trying to escape Chemical Plant Zone. With the group in the Mean Bean Machine, the doctor challenged the heroes to another puzzle game. However, Eggman was once again outplayed, resulting in him getting dropped into a pipe after his machine blew up while the heroes escaped the Mean Bean Machine unharmed.


The Mean Bean Machine is the second boss of Chemical Plant Zone, and the fourth overall boss of Sonic Mania and Sonic Mania Plus. It is fought at the end of Chemical Plant Zone Act 2.

In Sonic Mania, the Mean Bean Machine is fought with Sonic, Tails or Knuckles. In Sonic Mania Plus, it is fought with Sonic, Tails, Knuckles, Mighty or Ray.

Boss guide

This boss battle begins right after passing through a high-speed warp tube. The Mean Bean Machine is different from any boss in Sonic Mania. Instead of fighting Dr. Eggman or one of his robots with normal attacks, the player must instead compete against the computer in a puzzle game. This means the player cannot get a bonus for an "All Clear". The game begins when the playable character is in the Mean Bean Machine. Once inside, all regular gameplay maneuvers are disabled, and counterattacking Eggman is not possible. Also, all Super States get deactivated upon entering.

The Mean Bean Machine boss fight follows the standard rule of the Puyo Puyo series. The gameplay takes place across two 6 x 12 grid-based boards. The left board is used by the player, while the right board is used by Eggman. The objective is to keep the player's board clear by grouping certain Puyos together as they fall down on the board from the top in groups of two. One pair of Puyos will fall each "turn". The Puyos themselves come in five different colors: red, green, blue, yellow, and violet. The player must arrange the Puyos into groups of at least four Puyos in the same color; should they do this, the Puyos in the group will disappear. Both boards can hold a total of seventy-eight Puyos. The game is over once a participant's third column from the left of their cabin pile up to the top of the board; in the player's case, they will fall into a bottomless pit as their penalty. Fortunately, Eggman has weak player AI, so he should not be difficult to beat.

While Puyo fall down, the player can move them left or right, rotate their formation and speed up their descend. If a Puyo block is placed on a Puyo formation so one Puyo protrudes over an edge, said Puyo will split off and continue its descend. Also, above the cabins in the center of the screen, the player can see the next Puyo block that will be deposited on the boards next.

When making a group of Puyos disappear, other Puyos stacked on top of them drop a level. The player can organize these Puyos by placing Puyo blocks conveniently close to each other, so when one group disappears, other similarly-colored Puyos drop down together, thus triggering a chain reaction that cause another set of Puyos to group and disappear, and so on. Each link in a chain reaction will also cause transparent Garbage Puyos to be deposited in random places on the rival's board. These Puyos can only be eliminated by having them touch a cluster of disappearing Puyos. The amount of Garbage Puyos dumped depends on the length of the chain that created them; one group of Puyos disappearing creates a single Garbage Puyo, while multiple chain reactions produce large rows of Garbage Puyos. A player can attempt to send Garbage Puyos to Eggman in order to frustrate his attempts to remove his Puyos.

Because of the random nature, the time limit is frozen for the duration of this boss fight. Upon Eggman's defeat, his cabin will explode, and Eggman himself will be dropped into the bottomless pit. The player can then proceed to the Capsule and finish the Zone.


Name Artist(s) Length Music track
"Eggman Mean Bean" Tee Lopes 2:17



Sonic Mania Boss 4 - Mean Bean Machine


  • The Mean Bean Machine utilizes the signature gameplay style and elements from the Puyo Puyo series and the spin-off Sonic the Hedgehog title, Dr. Robotnik's Mean Bean Machine.
    • Its name is borrowed from the said game's title or perhaps the titular Mean Bean-Steaming Machine.
    • This boss also features a remixed version of the track "Final of Puyo Puyo"/"2 Player vs.". It was also the theme of Satan/Dark Prince from the Puyo Puyo series.
  • If the player collects twenty-one medallions in Sonic Mania, they will unlock Mean Bean, which is a minigame based on the Mean Bean Machine fight where the player plays a best-of-3 match against the computer or another player.
  • On the official Japanese website for Sonic Mania, this boss battle was hinted as a "surprise ending" to Chemical Plant Zone Act 2.[2]


  1. While not listed in any instruction manuals, the internal files in the PC release of Sonic Mania have many sprite files under the CPZ file path (Chemical Plant Zone) that have abbreviation "MBM" on them (like "Data/Sprites/CPZ/MBMSonic.bin" and "Data/Sprites/CPZ/MBMKnux.bin"), which most likely refers to "Mean Bean Machine". Additionally, the sound track for this boss in the D.A. Garden of Sonic Mania is named "Mean Bean Machine".


  1. 1.0 1.1 Johnathon Dornbush (2 October 2017). Sonic Mania Dev on Origins of Easter Eggs, Sega References. IGN. Retrieved on 17 November 2017.
  2. Takahashi, Dean . Hands-on with the Hedgehog’s return to 2D in Sonic Mania. Venture Beat. Retrieved on June 2017.

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