Here is the full list of all 29 GYLT achievements.
Escape with Emily
Escape from Helplessness
Reach the Final Mine
Defeat Violence
Freeze one Enemy of Each Type
Reach the Basketball Court
Freeze an Enemy and Push Him
Access the Art Building
Defeat Exposure
Get into the Theater
See the weirdness in the school
Escape from the Arcade without being detected by Exposure
Try to Play other of Tequilaworks Game
Remove the battery from the Arcade core
Blind Three Enemies at the Same Time
Kill an enemy with a Stealth Attack
Get outside of the school courtyard
Defeat an Enemy with the Flashlight Beam
Free all the Inhabitants
Get all the Diaries
Enter the school looking for Emily
Use the Planks to Remain Dry
Escape with Sally
Escape with Both Sally and Emily
Defeat Violence in the Laboratory Without Being Hit
End the Game without Killing Anyone (without bosses)
Hoop a can
Shock an Enemy
Hit an enemy with a can