Here is the full list of all 31 Pummel Party achievements.
Score over 5 in 'Bouncing Balls'
Knock off 5 players in one game of 'Snowy Spin'
Take no damage in 'Searing Spotlights' minigame
Survive in 'Breaking Blocks' for 60 seconds
Start your first game
Get launched off screen in 'Tunneling Tanks'
Accidentally blew yourself up in the 'Strategic Shockwave' minigame
Get a 5 player kill sreak in 'Speedy Sabers'
Collect 40 keys in 'Winter Maze'
Get a double kill in 'Barn Brawl'
Died in 'Acidic Atoll' throwing a barrel
Win your first game
Complete 'Slippery Sprint' without falling in the water
Get your first goal
Steal the last gift in a players pile in 'Grifting Gifts'
Win your first minigame
Control over 50% of the area in 'Elemental Escalation'
Hit three players with the remote control eggplant
Skewer three players with the rocket skewer item
Place first in every minigame
Place last in every minigame
Survive for 50 seconds in 'Bullet Barrage'
As the lightning holder kill every other player in 'Thunderous Trench'
Knockout 10 players in one game of 'Explosive Exchange'
Complete 'Rusty Racers' without falling off the track
Survive for at least 50 seconds in 'Sorcerers Sprint'
Got hit by the train in 'Temporal Trails'
Find the treasure in 'Sandy Search'
Win 'Magma & Mages' without taking damage
Complete 'Gift Grab' without collecting coal