Here is the full list of all 40 Defend The Highlands achievements.
Get 500 kills with Queen Boadicea
Get 500 kills with William Wallace
Recruit 1,000 Scotsmen in total
Kill 500 enemies with whisky vomit
Kill 1,000 enemies with golf balls
Kill 10,000 enemies
Kill 1,000 enemies with turnip turrets
Kill 15 enemies with Nessy in a single match
Kill 500 enemies in melee
Kill 1,000 enemies with porridge cannons
Kill 500 Welsh Sheep Riders
Kill 250 enemies with bagpipe artillery
Kill 1,000 enemies with haggis catapults
Kill 500 Leprechauns
Kill 500 Posh Englishmen
Kill 500 Beefeaters
Kill 500 Ancient Briton Warriors
Get 500 kills with Robin Hood
Hit 5 enemies with a single artillery strike or haggis
Complete a skirmish match on easy
Complete a skirmish match without heroes
Defeat a level 6 enemy on level 1 in skirmish mode
Complete a skirmish match on medium
Complete a skirmish match without towers
Complete a skirmish match on hard
Complete a skirmish match on impossible
Kill 500 enemies with cheese wheels
Fully upgrade all stats on a single unit
Kill 1,000 enemies with porridge bowls
Kill 500 English Cricket Players
Have 50 Scotsmen at once
Kill 500 Irish Potato Farmers
Kill 500 Welsh Rugby Players
Get 500 kills with Alfredo
Have 2,000 gold at once
Kill 1,000 enemies
Have 5,000 porridge at once
Recruit 100 Scotsmen in total
Fully upgrade a stat
Kill 100 enemies