Here is the full list of all 8 Dead Secret Circle achievements.
Complete the game
Find the final Dogu statue
Complete the game and find all the hidden audio cassettes
Complete the game and find the secret message in the mirror
Complete the game and solve a Puzzles Quarterly magazine
Complete the game and translate Rose's document
Complete the game and clean up the spill in Colm's room
Complete the game and find the Wind-up Knight toy