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