To get Alchermistman and Bloonacleboy in BTD6, you need to earn the hidden achievement by dealing 900,000 damage with a Bloon Master Alchemist before round 100 ends.

What to do

  • Start a game on an easy map, often one with a simple track like Resort or Monkey Meadow.
  • Build up to a Bloon Master Alchemist and keep it attacking bloons as much as possible.
  • Use support towers and upgrades that help the Alchemist hit more bloons or survive longer, such as Village support, Spike Factory backup, and stall/control towers.
  • Finish the 900k damage requirement before round 100, then return to the main menu to claim the achievement.

After unlocking it

Once the achievement is claimed, go to Settings > Extras and turn on Small Bloons.

Simple version

  1. Play an easy map.
  2. Build and upgrade Alchemist into Bloon Master Alchemist.
  3. Get 900k damage before round 100.
  4. Claim the achievement.
  5. Enable Small Bloons in Extras.

A common strategy is to use cheap early defense, then let the Bloon Master Alchemist rack up damage in free play while support towers keep bloons on screen longer.