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