Here is the full list of all 27 Harold Halibut achievements.
Complete the game.
Complete Chapter 6.
Complete Chapter 5.
Untangle the story of the brothers.
Complete Chapter 4.
Listen to all of the gossip at Gertrude's Bierzone.
Read and deliver all of Buddy's letters.
Help Slippie set up in the Energy Disctrict.
Talk with everyone about the exchange.
Convince Warren to move Water Wieners to the Cave.
Complete Chapter 3.
Complete Chapter 2.
Support Captain-at-large Zoya during all walks of life.
Clean all of the graffiti.
Watch Onat's stage performance.
Listen to the Announcer under the shower.
Complete Chapter 1.
Try to pick up the sample directly from Brigitte.
Update Mareaux about every step of the search for the Blue Rock.
Participate in the station jog.
Play Rapid Fly Zone Force for 2 Minutes.
Try out Slippie's ski slope.
Watch TV for 10 minutes.
Make your first trip on the All Water tube.
Attempt to leave the All Water Office 3 times.
Complete the Notebook.
Enjoy the game at a leasurely pace (more than 15 hours play time.)