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.
Grabbed an unaware Gunk Spitter
Made one charge into another
Installed all upgrades
Saved the day
Filled the encyclopedia
Make one charge off a cliff
Blasted three to smithereens
Got out of the Wasteland
Found the Garden
Defeated the Gunk Beast
Cleared the Gunk Tower
Installed five upgrades
Set up Camp
Scanned fifteen objects
Threw one on another
Landed the Dust Bunny
Cleared the first Gunk