The Zomboss Down Title update for Plants vs. Zombies Garden Warfare has 10 achievements worth 250 gamerscore.
Be on the Winning Team for 15 matches of Gnome Bomb
Vanquish 10 Enemies while They are Carrying a Gnome Bomb
Defuse a Gnome Bomb with Less Than 3 Seconds Remaining
Defuse 3 Gnome Bombs
Summon a Barrel Pirate and Map Pirate Zombie in Gardens & Graveyards
Push the Golf-Bomb into the Hole in Cactus Canyon
Grow a Doom-shroom, Bamboo Shoot, Fire Peashooter and Ice Peashooter
Plant 5 Gnome Bombs
Vanquish 500 Pirate Zombies
Pick up a Gnome Bomb