Here is the full list of all 12 Worms achievements worth 200 gamerscore. It takes around 8-10 hours to unlock all of the achievements on Xbox 360.
Complete training
Complete all 20 single player challenges
Inflict 500 damage
Inflict 2,000 damage
Inflict 20,000 damage
Kill 3 worms with one shot
Kill 100 enemy worms
Collect 50 crates
Blow up 25 barrels
Trigger 25 Mines
Kill 15 worms using only Sheep
Play a four player Xbox Live game.