Here is the full list of all 17 The Gunk achievements. It takes around 4-5 hours to unlock all of the achievements on Windows.
Saved the day
Filled the encyclopedia
Installed all upgrades
Got out of the Wasteland
Made one charge into another
Found the Garden
Blasted three to smithereens
Defeated the Gunk Beast
Grabbed an unaware Gunk Spitter
Cleared the Gunk Tower
Make one charge off a cliff
Installed five upgrades
Set up Camp
Threw one on another
Landed the Dust Bunny
Scanned fifteen objects
Cleared the first Gunk