Here is the full list of all 14 Phase Ninja achievements.
Kill Your First Enemy
Kill 5 enemies in one level
Kill 10 enemies in one level
Kill 20 enemies in one level
Kill 25 enemies in one level
Win the farm level
Win the ember forest level
Win the astor plains level
Win the nova town district 1 level
Win the nova town district 2 level
Win the cursed forest level
Win the demonic cave level
Defeat the evil wizard
Congratulations! You beat the game