i am glad you liked the pixel art!
To pickup keys and open doors, you need to left click on your mouse! But, after picking up the note with a key, you only need to close it by pressing the x button.
To talk with the girl further, after clicking e on your keyboard 1 time to start talking, you will need to left mouse click every time the sentence of a characte completes to continue to the next one just like the metic dialogue!.
I really forgot to add invisible blocks until the last minute to stop player from falling into the void which is why i also added tasks xd. So to play the game correctly you pretty much just need to follow the tasks. The controls used in most of the stuff is left mouse click. E is only used to start talking with the girl npc.
For example: you want to play the item given by girl -> go and sit on the desk in your room and click on the item
If you have anymore questions feel free to ask! I will try responding to it