Here is the full list of all 23 No Creeps Were Harmed TD achievements.
Open the “How To Play” menu and learn stuff
Complete one map
Complete five maps
Complete ten maps
Complete fifteen maps
Complete twenty maps
Fail a map
Let Brian Jar die!
Get five levels deep into endless mode
Complete a time bonus sub-objective
Complete the kill-all-creeps sub-objective
Order Brian Jar to move
Use one of Brian’s special abilities.
Configure a turret by changing its targeting priority
Upgrade a turret
Destroy a Gleep container before the map wave goal
Sell an Artifact
Play with a friend
Get a level-up
Get ten level-ups
Get fifty level-ups
Rush a wave
Complete 42 maps