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