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