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