Small Bloon Option

"You have it set to M for mini, when it should be W for wumbo"

- "Alcheristman and Bloonacleboy" BTD6 achievement description

 is a setting in Bloons TD 6, added in Version 12.0. It is unlocked after beating a secret achievement called "Alchermistman and Bloonacleboy". This can be completed and revealed when a Bloon Master Alchemist has 900,000+ damage in a single game  before completing Round 100  (game MUST be ended before starting Round 101). The gamemode does not have to be completed to unlock the achievement. Similarly to Big Bloon Option, the effect is purely visual, and it can be enabled on CHIMPS Mode. Prior to Version 17.0, enabling both options would simply cancel each other's effects out.

Unlike Big Bloon Option, Small Bloon Option can be advantageous on occasions where the player would need to see through massive rushes of bloons. For instance, it is easier to see certain bloons between dense groups of normally large bloons, especially on Race Events. There are no gameplay mechanic benefits or downsides, however.

Summary
Let Bloon Master Alchemist make as many pops as possible before completing Round 100. Farm super hard while keeping a solid flow of income. Bloon Master Alchemist steals income by transforming affected bloons into measly Red Bloons, hence the need to sustain more income for handling faster bloons. Towers that can buff the alchemist whilst not stealing any pops for themselves can also be particularly useful, such as an Overclock Engineer placed far from the track, or a Monkey Village.

Tips

 * The achievement can be obtained in Co-Op Mode, and only one player needs to place the Alchemist for everyone to obtain the achievement.
 * It can be earned in any game mode and Freeplay.
 * From round 90-99 there is a total of around 1.1 million RBE.
 * Glue Gunners can help keep bloons in range of BMA, whilst slowing them down.

Trivia

 * Both the achievement's name and the description are clear references to the TV Show SpongeBob SquarePants. Specifically, the former is a reference to Mermaid Man and Barnacle Boy, while the latter is a reference to a quote in the episode Mermaid Man and Barnacle Boy IV.
 * However, the actual quote is: "You got it set to 'M' for Mini, when it should be set to 'W' for Wumbo."