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