Here is the full list of all 16 Jolly Rover achievements. It takes around 4-5 hours to unlock all of the achievements on Windows.
Earned maximum score
Found all crackers
Found all pieces of eight
Found all pirate flags
Completed game without hints
3x coconut knock-out
Escape in a hot air balloon
Defeated DeSilver
Rode a sea turtle
Found Silvereye's treasure
Sailed to Shipwreck Island
Infiltrated pirate stockade
Joined a pirate crew
Invented the trampoline
Escaped Howell's Ship
Sent a shipmate on a trip to remember