Here is the full list of all 33 Return of the Host achievements.
Kill two monsters in quick succession
Kill three monsters in quick succession
Kill four monsters in quick succession
"True courage is about knowing not when to take a life, but when to spare one" - Gandalf The Gray
You beat the game... or did you?
Complete level 1
Complete level 2
Complete level 3
Complete level 4
Complete level 5
Complete level 6
Complete level 7
Complete level 8
Complete level 9
Complete level 10
Complete level 11
Complete level 12
Complete level 13
Complete level 14
Complete level 15
Complete level 16
Complete level 17
Complete level 18
Complete level 19
Complete level 20
Complete level 21
Complete level 22
Complete level 23
Complete level 24
Complete level 25
Complete level 26
Complete level 27
Complete level 28