Here is the full list of all 13 Sir War-A-Lot achievements.
Kill 50 Enemies in one session
Kill 100 Enemies in one session
Kill 200 Enemies in one session
Locate the Eagle Crown
Complete the flying level
Defeat Dark Crow
Defeat Fire Golem
Defeat Frost Golem
Defeat Minotaur King
Locate the Green Gem in Forest Area
Locate the Blue Gem in Desert Area
Locate the Pink Gem in Castle Area
Purchase everything in the store