Menace from the Deep achievements

Defeat the Hastur boss fight

Make 3 purchases from the Merchant at the same time

Defeat the Dagon boss fight

Defeat the Ithaqua boss fight

Complete the story stage "Tension rises"

Level up The Monolith to level 20

Complete the story stage "Finding Allies"

Level up The Monolith to level 10

Unlock the Cultist in campaign mode

Collect the "Phrenology Bust" collection

Complete 3 acts on high difficulty with an increased number of enemies in "Custom Game" mode.

Collect the "Gas Mask" collection