Here is the full list of all 55 Party Crashers trophies - there are 47 bronze, 6 silver, 1 gold and 1 platinum.
Be on match point 3 times in a row without winning the match.
Win a round without using any pickups.
Die by driving off the track without help.
Win a round without dealing any damage to or killing other players.
Try all of the powerups.
Take the lead by using the speed boost pickup.
Launch a player into the air using the cowcatcher.
Kill 3 other players in a single round.
Win a round of any game mode.
Push another player off the track.
Get killed by driving off the track.
Get killed by falling too far behind the leader.
Successfully master all the ways to play Party Crashers.
Finish a round of at least ten of the Elimination game modes.
Finish a round of at least ten of the Race game modes.
Finish a round of at least ten of the Time Trial game modes.
Finish a round of at least ten of the Battle game modes.
Try all of the mutators.
Try a non-default setting from every deep customisation row.
All four human players are alive at the end of the round.
All four human players kill someone in the same round.
Your controller buddy won the match.
Finish a match in first and second place with your controller buddy.
Humans finish in 1st and 2nd in a two human versus two AI match, and only AI players are killed.
Change something using the mutators menu.
Use the customise menu.
Set some per-player options in the customise menu.
Find the deepest level of the customise menu.
Use the sliders to customise further.
Take the lead by shooting the leading player.
Hit 3 players with one railgun shot.
Play against three AI and get at least 10 kills before getting killed by an AI.
Win a match of the Speed Limit game mode.
Win a match of the Super Classic Arcade game mode on the Bends Track.
All four humans players get a sub 12 second lap time on the Figure 8 track in Best Lap Time game mode.
Win a match of the Kart Racing game mode.
Win any battle mode against other humans.
Win a match without dealing any damage to or killing other players.
Win a match without using any pickups.
Win every round in a match of 500 points.
Win a round while driving backwards.
Win 3 matches in a row in a single session.
Don't win a round in a match of 500 points or more.
Get killed 5 times in a row by falling too far behind the leader.
Lose the match after being on match point 5 or more times.
Fail to win the match even after winning the round while on match point.
Finish the match on a negative score.
Move from last place to first place in one round (against at least 3 competitors).
Win an elimination quick game with a score over 1000 points.
Win a match after there being 3 or more players on match-point above you.
Win a round with less than 5% health.
Be selected for the podium after a match ends in a tie.
Play 1000 rounds.
Win 100 matches.
Win a match of at least half of the gamemodes.