Is it possible in some way to alternate the "gravity" and the orientation of the camera?

How can I do it or if there is any way to do it and if not, well

It should be noted that I am new to Gdevelop and everything related to it but I don’t worry about that

There is rotate layer action

Do you want to change the direction of gravity? I don’t believe that’s possible. You could probably simulate gravity using forces. I’ve been wanting to play with the concept of rotating a room. Stick all the of objects to a center object using the sticker behavior and then rotate that object. The character could walk on the walls and the ceiling . The camera could also be rotated or not.

You can change world gravity if you are using the physics behaviour. And to change camera orientation, you can rotate the camera of a layer.