Here is the full list of all 20 PHAT PHROG achievements.
Reach a high score of 5000
Achieve 150 points on Challenge 1
Reach a score of 2500
Reach a high score of 7500
Reach a high score of 10,000
Unlock the Neenja Phlam costume
Unlock the Frozen Phlam costume
Unlock the Pharaoh Phlam costume
Unlock the Pirate Phlam costume
Achieve 1000 points on Challenge 3
Achieve 1200 points on Challenge 3
Achieve 1500 points on Challenge 3
Achieve 2000 points on Challenge 3
Achieve 150 points on Challenge 2
Achieve 250 points on Challenge 2
Achieve 350 points on Challenge 2
Achieve 500 points on Challenge 2
Achieve 250 points on Challenge 1
Achieve 500 points on Challenge 1
Achieve 1000 points on Challenge 1