Here is the full list of all 15 Selfless Heroes achievements.
Get 10 stars
Get 25 stars
Get 50 stars
Get 90 stars
Get 125 stars
Get 160 stars
Get all stars
Defeat the ogres
Defeat the pied pipper
Defeat Kronos
Defeat the mad gatekeeper
Defeat the infestation
Win a level with a solution shorter than the code length secondary objective
Over 1000 runs
Win all levels