Here is the full list of all 12 Filthy Stinking Orcs achievements.
Survive the tutorial
Get 100 kills with archery
Get 100 kills with cannons
Get 100 kills with the machine gun
Get 100 kills with the howitzer
Kill 500 Orcs
Kill 500 Goblins
Kill a Colossus
Kill a Dragon
Get 100 kills with mines
Get 20 kills with boiling oil
Don't let 5 Hamlets take any damage