Here is the full list of all 11 Mystic Defense achievements.
Achieve one star on every level.
Achieve two stars on every level.
Achieve three stars on every level.
Kill 500 enemies.
Kill 1,500 enemies.
Kill 5,000 enemies.
Collect 10,000 spell points.
Collect 100,000 spell points.
Collect 500,000 spell points.
Beat all levels without getting hit.
Beat all goal times on every level.