The Multi Player Pack Add-on for Worms Ultimate Mayhem has 6 achievements.
Play each new map more than 5 times (all modes count)
Drown 20 Worms across any of the new maps
Play an online game on each new map and win, proving you’re the greatest general
Can you rise to the challenge and win a ranked Deathmatch on every new map?
Win a ranked match with two or more worms remaining on each new map
Win a ranked Deathmatch on a new map with at least one worm ending with more health than they started with