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