Here is the full list of all 74 Deadlink achievements.
The base game contains 70 achievements, and there is 1 DLC pack containing 4 achievements.
Survive 20 waves in Extant Existence mode.
Survive 40 waves in Extant Existence mode.
Survive 50 waves in Extant Existence mode.
Survive 100 waves in Extant Existence mode.