Here is the full list of all 16 Phantom Trigger achievements.
Die in co-op mode
Kill 20 enemies in co-op mode
Congratulations, you skipped the story
Did you read the text at the very end of the game?
Do you know what insanity is?
Turn off the last TV set
Take a trip with Pam
The tree falls!
Unlock all combos
Smash all crystals
Kill everyone
Solve all puzzles
Beat all bosses in co-op mode
Kill 50 frozen enemies
Chop down the tree
Arena completed.