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