Here is the full list of all 38 Just Dance 4 trophies - there are 20 bronze, 13 silver, 4 gold and 1 platinum.
Obtain All Other Trophies
Burn 2000 Calories in Sweat Mode
In any Dance Crew Song, All Four Players Get 5 Stars (Four Coaches)
In any Dance Crew Song, All four Players Get 3 Stars or better (Four Coaches)
Dance to We No Speak Americano with 3 others
Burn 1000 Calories in Sweat Mode
Perform only Good Moves or better in 5 Songs
Perform only Good Moves or better in a Song
Complete at least one Class from each of the 5 Sweat Programs
Burn 500 Calories in Sweat Mode
Win each Battle Once
Get 5 Stars on All Songs (No Alternate Versions, Mash-Ups or Battles)
Get 3 Stars on All Songs (No Alternate Versions, Mash-Ups or Battles)
Win a Battle
Win a Battle as the Never Gonna Give You Up Coach
Complete a full 45 Minute Sweat Class
Get 5 Stars on the Extreme Version of Wild Wild West
Dance to (I've Had) The Time of my Life Alone
Get 5 Stars on a Song with Pictograms Disabled
Finish a Duet with 2 players getting 5 Stars on both Choreographies
Complete a full 25 Minute Sweat Class
Complete a full 10 Minute Sweat Class
Complete a Sweat Class
Get 5 Stars on any Mash-Up
Dance to the Same song 3 times in a row
Dance to Time Warp twice in a row
Get 5 Stars on 5 Songs
Perform all Gold Moves in 5 Songs
Get 3 Stars on 5 Songs
Unlock an Item from the Wheel of Gifts
Complete 5 Dance Quests
Complete your First Song
Get a Perfect on the Last Move of a Song
Complete a Song with 80% or more Perfect Moves
Perform all Gold Moves in a Song
Get 5 Stars on a Song
Get 3 Stars on a Song
Get 10 Perfect Moves in a row in any song