Here is the full list of all 22 Lil Gator Game achievements. It takes around 3-4 hours to unlock all of the achievements on Windows.
Undertake a new, bigger quest.
Completed Avery's Quest
Completed Martin's Quest
Completed Jill's Quest
Complete the story.
Break everything on the island.
Make friends with everyone on the island.
Acquire all bracelets, and gain enlightenment.
Take a seat in the Junk Shop.
Equip the full space set.
Equip the full paint set.
Equip the full ninja set.
Craft every item.
Learn the monkey's name.
Learn the monkey's real name.
Instruct the monkey on the power of creativity.
Learn the monkey's TRUE name.
YOU WILL NEVER KNOW THE TRUTH.
Climb to the tippy top of the antenna.
Try to touch the sky.
Ragdoll into something as fast as you can.
Swing with the Sticky Hand 5 times without touching the ground.