Here is the full list of all 12 Forest Grove achievements.
Submitted your first case report
Aligned all the hovercams in the house and have the report desk unlocked
Listened to all the audio fragments in the house
Found Zooey's secret playroom
Found Max's secret area
Set the time on the grandfather clock correctly
Played the piano and opened a secret closet
Discovered how dearly Max misses his wife, Rebecca
Found a way into the Nanodeck
Found some incriminating phone/laptop messages
Solved the case
Reached the highest grades as an investigator