CAKE

Credits to Sculpture for the text showing after collecting notebook (Harrytuts). 

More credits are in the game. 

How to play:

Step 1: Go to the store

Step 2: Buy a Computer

Step 3: Install Windows

Step 4: Go to itch.io

Step 5: Download the game

Step 6: Extract it

Step 7: Launch the Exe

Step 8: have fun