Here is the full list of all 27 Skulls of the Shogun achievements.
Complete the Forbidden Islands on Normal difficulty.
Complete the Forbidden Islands with 10 units or more.
Complete the Land of Frozen Fortunes on Normal difficulty.
Acquire your first "Very Rare" emblem.
Earn 30 gold skulls.
Complete the Land of Golden Harvest on Normal difficulty.
Defeat a General with a Tanuki taunt.
Knock 3 foes off a ledge at once with a Demon Crow Monk's Typhoon spell.
Complete the Land of Monsoon Meadows on Normal difficulty.
Defeat 5 foes at once with a Salamander Monk's Lightning Storm spell.
Earn 15 gold skulls.
Complete the Land of Eternal Blossoms on Normal difficulty.
Bring back a fallen unit with a Demon Fox Monk's Revive spell.
Defeat an enemy Monk by haunting its Shrine.
Complete the Shores of the Dead on Normal difficulty.
Win a 4-player online multiplayer match.
Win a team deathmatch game with your teammate still alive.
Win an online match that lasts at least 30 rounds, defeating at least 30 enemies.
Break a Deadly Alliance in online multiplayer.
Win a multiplayer match with a 20-second-per-turn time limit.
Win an online multiplayer match.
Power up your General to a Demon.
Earn 60 gold skulls.
Complete every level such that your best times for all of them add up to less than 4 hours on Normal difficulty.
Acquire 100 emblems.
Have an emblem upgraded to Gold status.
Earn all 72 of the Bone-A-Fide Edition Gold Skulls.