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