Here is the full list of all 25 Down in Bermuda achievements. It takes around 3-4 hours to unlock all of the achievements on Windows.
Pull up your explorer socks and complete the tutorial.
Find all Orbs in the Turtle Island.
Complete all stats for Turtle Island.
Find all Orbs in the Secret Base Island.
Complete all stats for Secret Base Island.
Find all Orbs in the Forest Island.
Complete all stats for Forest Island.
Find all Orbs in the Shipwreck Island.
Complete all stats for Shipwreck Island.
Find all Orbs in the Lava Island.
Complete all stats for Lava Island.
Complete all stats for Labyrinth Island.
Help Milton to escape the Bermuda.
Help Milton to escape the Bermuda without opening a single Star Map.
Collect all Relics and then pay a visit to the Relic Monument.
Sort the sheep into their correct pens within 200 seconds of the gate opening.
Vanquish the Kraken in 7 shots of the cannon.
Solve the tricky orange liquid levers puzzle in Secret Base Island.
Unlock the mine cart in Shipwreck Island.
Defeat the almighty Fire God and gain some new worshippers, Oonga Oonga!
Complete the tile sliding puzzle in Labyrinth Island within 14 moves.
Inflate any puffer fish 10 times.
Shoot 12 barrels in Secret Base Island.
Open the door to Quack's hut three times.
Shoot 50 cannon balls in Shipwreck Island.