Here is the full list of all 14 Christmas Blaster achievements.
Play with a friend.
Kill the Big Bad Snowman at normal level.
Destroy Christmas Smash Machine at normal level.
Kill the Krampus at normal level.
Complete Bonus 01.
Complete Bonus 02.
Finish the game without dying.
Destroy Christmas Smash Machine without dying.
Kill the Big Bad Snowman without dying.
Kill the Krampus at hard level.
Collect 500 Gifts in the same match.
Find the Golden Sculpture.
Find the Silver Sculpture.
Find the Bronze Sculpture.