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