Here is the full list of all 45 AI: The Somnium Files achievements. It takes around 20-25 hours to unlock all of the achievements on Windows.
Obtained all other trophies.
Found all hidden items in Somnium.
Collected all the "Dream Album" files.
Confronted So with the evidence with no mistakes.
Confronted Ota with the evidence with no mistakes.
Confronted Iris with the evidence with no mistakes.
Cleared the shooting event at the Sagan residence with no misses.
Cleared the shooting event at the Sejima residence with no misses.
Almost got cursed by Adorabbit in Somnium.
Discovered the marriage of the yakuza and the nurse.
Admired the Sagan's stereo equipment.
Checked absolutely everything in Boss's office.
Finished the final investigation.
Kept your cool and did not shoot Saito.
Collected all the "Persons" files.
Day 6: Wednesday - Cleared Saito's Somnium.
Finished Annihilation Route investigation.
Day 5: Tuesday - Cleared Boss's Somnium.
Day 5: Tuesday - Cleared Hitomi's Somnium.
Confronted Hitomi with the evidence with no mistakes.
Finished Iris's investigation.
Day 5: Tuesday - Cleared Iris's Somnium.
Found 6 hidden items in Somnium.
Saw This Man twice in Somnium.
Cleared the shooting event at the Warehouse District with no misses.
Day 4: Monday - Cleared Iris's Somnium.
Collected 100 "Appendix" files.
Cleared the shooting event at Golden Yokocho with no misses.
Day 3: Sunday - Cleared So's Somnium.
X-rayed the Mermaid.
Day 4: Monday - Cleared #89's Somnium.
Had Aiba wear the basket and the pot in Somnium.
Finished Ota's investigation.
Day 5: Tuesday - Cleared Mayumi's Somnium.
Saw three autographs of crazy customers in Somnium.
Finished Mizuki's investigation.
Day 6: Wednesday - Cleared Date's Somnium.
Asked out the receptionist to Atami.
Day 4: Monday - Cleared Ota's Somnium.
Day 3: Sunday - Cleared Iris's Somnium.
Cleared the shooting event at the Kumakura office with no misses.
Enjoyed a fulfilling chat with Kagami.
Day 2: Saturday - Cleared Mizuki's Somnium.
Day 1: Friday - Cleared Date's Somnium.
Found 1 hidden item in Somnium.