Full list of all 12 Back In 1995 achievements worth 1,000 gamerscore. It takes around 1-2 hours to unlock all of the achievements on Xbox One.
Get the shotgun.
Clear the second stage.
Get the pistol.
Clear the first stage.
Get the pipewrench.
Clear the opening sequence.
Clear the third stage.
Clear the fourth stage.
Complete game with first ending.
Complete game with second ending.
Get the flashlight.
Collect Dr. Randell newsclips.