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.
Obtained the old man's artefact in the sea.
Rejected all the assassination contracts.
Have overcome 25 random encounters in the sea.
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.
Fulfilled all the assassination contracts.
Looted all treasure chests and hidden caches.
Visited all islands.
All pirate tricks learned.
Jarl Erik defeated.
Bought an item for hero.
Have answered all the questions of the sages.
All four equipment items on.
Fought through all dungeons and arenas.
Rejected the Iron Bank's offer.
Sir Rodrick defeated.
Six pirate tricks learned.
Davy Jones defeated.
Looted 7 treasure chests and hidden caches.
Page on Facebook or Twitter visited.
Pirate trick learned.
You defeated the army without losing a single warrior.
Cabin boys have joined you.