Here is the full list of all 25 Blair Witch achievements.
Collect all wooden dolls.
Collect all victim's photos.
Help Ellis to get his redemption.
End the game without killing any monsters
Collect all of the psychiatrist's notes.
Pick up all the trash.
Pay your respects to sheriff Lanning.
Let Bullet bring you 10 things
Find out what happened to Peter.
Become Carver
Find out what happened to Bullet.
Break 10 totems.
Patch things up with Jess.
Let the VA know about the lumberjack's death.
Collect all dog tags of the fallen comrades.
Kill 10 monsters.
Collect the first dog tag.
Walk 100 miles...
Kill your first monster.
Collect the first victim's photo.
Collect the first wooden doll.
Make the pizza guy lose it.
Pet the dog
Collect the first psychiatrist's note.
Score 40 points in Cobra.