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