Hints and puzzle solutions list
In the infinite corridor, you gotta open the 5th door to the right. The door right in front of you is the 1st one, so you gotta count 4 more. Don’t interact with the doors until you reach the 5th or else you’ll be reset to the 1st door. Going left also resets you to the 1st door.
The piano puzzle is the first 3 letters of the professor’s name plus the first 3 letters of his surname. You’ll find his surname on the school board on the entrance and his first name on the music room.
In the forest, there’s a hidden door that will reveal itself when you point the smartphone’s lantern at it. It’s located north of the save point.
To block enemy attacks you have to stay still and point the mouse or right analog stick in the direction of the attack.
The boss is invincible until they miss their special attack, telegraphed by a lightning animation. This attack is unblockable, so you have to hide behind a pillar. Doing an attack of your own to the side at the last moment can also help you avoid their special attack.