Here is the full list of all 25 Crush Your Enemies achievements.
Collect 200 pints of beer.
Complete Brog The Barbarian's campaign.
Use the Dummy Barbarian 10 times.
Use the Shroom Moonshine 10 times.
Impale 50 of your enemies' heads.
Collect 50 pints of beer.
Crush 1,000 Generian fighters.
Impale 20 of your enemies' heads.
Lose a battle.
Collect your first beer.
Win the first battle in Generia.
Impale 3 of your enemies' heads.
Complete Fuzgut The Destroyer's campaign.
Collect 500 pints of beer.
Impale 123 of your enemies' heads.
Crush 10,000 Generian fighters.
Crush 20,000 Generian fighters.
Crush an enemy group using Warriors and Archers with Wizards to support them both.
Complete 3 objectives in 4 different battles in a row.
Kill 40 enemies at once with your Spiky Mine.
Win a multiplayer battle.
Win 10 multiplayer battles.
Play 100 multiplayer battles.
Lose multiplayer battles in 5 different locations.
Take over all the farms and survive until the enemy has no food left.