Here is the full list of all 29 Musashi vs Cthulhu achievements.
Kill 150 Cultists.
Kill 700 Cultists.
Kill 2000 Cultists.
Kill 50 Maggots.
Kill 200 Maggots.
Kill 500 Maggots.
Kill 50 Insects.
Kill 200 Insects.
Kill 500 Insects.
Kill 75 Deep Ones.
Kill 300 Deep Ones.
Kill 1000 Deep Ones.
Kill 20 Dimensional Shamblers.
Kill 180 Dimensional Shamblers.
Kill 350 Dimensional Shamblers.
Take a look at the credits!
Face Cthulhu!
Travel the whole scenario in one match
Kill 50 Enemies without taking a hit
Kill 150 Enemies without taking a hit
Kill 300 enemies without taking a hit
Reach 50 Score
Reach 100 Score
Reach 250 Score
Reach 600 Score
Reach 1000 Score
Kill 10 Hounds of Tindalos
Kill 50 Hounds of Tindalos
Kill 100 Hounds of Tindalos