What is the most efficient way of making the world art/levels ?
I mean, should I draw the whole level in photoshop for example, and then add to unity the image and fit on it colliders?
Or is there better and faster procces?
Ye, draw a tree, for example, import it, add an collider and save it as a prefab, and now you have a ne gameobject tu fill your world
What about the floors/walls?
The same, you draw them, import them, add the things that you wants for them, and you save them as a prefabs for beign placed as your wis
Sorry, if i didnt answer, but im not sure of understand the problem, save them as png?
What you describe is definitely not the good process for level design.
For level design you will need to test and fix, the jumps, lengths of walkable etc.
You must be able to move around your interactables in your scene !
If you do need to create a beautiful entire asset (which I don’t recommend) you should first stick with a dirty quick drawn prototype so you can keep on testing and developing until you are sure your level won’t need further modifications…
But again, don’t work that way.