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