Here is the full list of all 26 Braveland Pirate achievements. It takes around 15-20 hours to unlock all of the achievements on Windows.
Rejected all the assassination contracts.
Have won 150 battles.
The Great Reaper defeated.
Game completed without using the easy level of difficulty.
Game completed using only the hard level of difficulty.
All the bosses defeated.
Looted all treasure chests and hidden caches.
Fulfilled all the assassination contracts.
Obtained the old man's artefact in the sea.
Rejected the Iron Bank's offer.
Have overcome 25 random encounters in the sea.
Visited all islands.
All pirate tricks learned.
Have answered all the questions of the sages.
Jarl Erik defeated.
Six pirate tricks learned.
Fought through all dungeons and arenas.
All four equipment items on.
Sir Rodrick defeated.
Bought an item for hero.
Page on Facebook or Twitter visited.
Davy Jones defeated.
Looted 7 treasure chests and hidden caches.
Pirate trick learned.
You defeated the army without losing a single warrior.
Cabin boys have joined you.