Here is the full list of all 21 Frozen Free Fall: Snowball Fight achievements.
Complete 50 Snowball Fights
Obtain a total of 500 Stars
Beat your opponent with 10 different characters
Combine 10 Iceberg and Glacier gems
Dodge 3 snowballs in a round
Combine 20 Windchill and Glacier gems
Combine 5 Double Glacier gems
Combine 15 Double Iceberg gems
Throw 3 super snowballs in a round
Combine 30 Windchill gems
Combine 25 Windchill and Iceberg gems
Throw 10 snowballs in a match
Finish the first 100 Winter levels
Obtain a total of 100 Stars
Obtains 150,000 points on one level
Obtain a total of 1 Million points
Obtain 50,000 points on one level