Here is the full list of all 7 Ruination achievements.
Decommission the watcher in the core with the starter pistol.
Demolish the monster in the depths in 192x144 resolution. Full screen must be disabled.
Exterminate the lord of the caves without taking damage.
Equipped every gun at least once.
Decommission the watcher in the core.
Demolish the monster of the depths.
Exterminate the lord of the caves.