Here is the full list of all 49 Dungeon Marathon achievements.
Get three stars on egypt floor 5
Get three stars on egypt floor 4
Get three stars on egypt floor 3
Get three stars on egypt floor 2
Get three stars on final floor 6
Get three stars on final floor 5
Get three stars on anthill floor 5
Get three stars on anthill floor 4
Get three stars on anthill floor 3
Get three stars on anthill floor 1
Get three stars on egypt floor 1
Get three stars on aztec floor 1
Get three stars on aztec floor 6
Get three stars on aztec floor 5
Get three stars on aztec floor 4
Get three stars on aztec floor 2
Kill three fairies at once...
Get three stars on magic floor 3
Get three stars on magic floor 6
Get three stars on magic floor 5
Get three stars on magic floor 2
Get three stars on magic floor 1
Get three stars on mines floor 6
Get three stars on mines floor 5
Get three stars on mines floor 3
Get three stars on mines floor 2
Kill two fairies at once...
Get three stars on final floor 4
Get three stars on final floor 8
Get three stars on final floor 7
Get three stars on final floor 3
Get three stars on final floor 2
Get three stars on final floor 1
Kill a single fairy...
Get three stars on crypt floor 6
Get three stars on crypt floor 5
Get three stars on crypt floor 3
Get three stars on crypt floor 4
Get three stars on crypt floor 2
Get three stars on crypt floor 1
Get three stars on egypt floor 6
Get three stars on anthill floor 6
Get three stars on anthill floor 2
Get three stars on magic floor 4
Get three stars on aztec floor 3
Get three stars on mines floor 4
Get three stars on mines floor 1
Beat the game in normal mode...
Beat the game in hard mode...