Here is the full list of all 28 Black Skylands achievements.
Defeat Ruth
Defeat Kain
Defeat the Devourer
Visit Swarm Territory
Defeat Rhoda
Get more than 17 000 Ship Steel
Get more than 17 000 Weapon Steel
Defeat Blast
Get 50 Weapon Mods
Get more than 6 000 Ship Steel
Defeat Mort
Get more than 6000 Weapon Steel
Liberate 10 Islands
Defend the Moth Village
Find 10 Chests of Gold
Get more than 1000 Ship Steel
Defeat Crash
Get more than 1000 Weapon Steel
Find 5 Chests of Gold
Get 5 Weapon Mods
Liberate Mills Island
Liberate 3 Islands
Complete the Prologue
Defeat Horos
Get All Weapon Mods
Obtain Steel Condor Crossbow
Liberate All Islands
Find All Chests of Gold