Here is the full list of all 15 Moonlight Minions achievements.
Build 25 towers in a single level
Defeat the Shelled Overlord Boss
Build 15 towers in a single level
Defeat the Dragon Boss
Last 50 waves
Last 75 waves
Last 100 waves
Beat the game on any difficulty
Beat the game on normal
Beat the game on hard
Kill a boss using the lightning ability
Stun 15+ enemies at once using the earthquake ability
Kill a boss using the meteor storm ability
Complete a map on hard without taking any damage
Pick up 25+ items on a single level