Here is the full list of all 20 Mastema: Out of Hell achievements.
Completed stage Soul cliff
Completed stage Flying fortress
Completed stage Evil forest
Completed stage Land of the bulbs
Completed stage Prison of madness
Completed stage Ancestral bones
Completed stage Eye of the Sphynx
Completed stage Anthil of death
Completed stage Red innards
Completed stage Deceitful sands
Completed stage Eternal ice
Completed stage Fiery ground
Completed stage Cursed galleon
Completed stage Screaming hanged men
Completed stage Infernal climb
Completed stage Green cave of desperation
Completed stage Field of thorns
Completed stage Idolatry of pain
Completed stage Altar of Mastema
Completed full game