Thank you so much RK Jain ! :D
No sorry there is only an official end. The door you are talking about cannot be opened and the other button of the elevator is simply used to go up in the house when you are in the underground corridor.
This is my first game and I wanted to make it short. I regret a little. if it had to be done again I would have added one or 2 elements. Like a puzzle with the pendulum clock that would have opened the door you're talking about.
There is, however, a secret ending ^^
The way to access it is revealed when you get 35/35 at the end ... But ... for some days now the way to access this end is on YouTube lol.