Change from 3D to 2D

Hi folks, I recently started a new project, but I'm stuck on one key asset of the game.
I want to switch from a 3D perspective to a 2D one, so all the objects in the 3d scene are brought to the front, and can be interacted with as if they were 2D. It's a bit like "Super Paper Mario" in which you can go in 3D and move around freely, but once you go in 2D there are alot of things in your way. (One example of this here)
I've tested some things out but can't really find a good solution, any help would be appreciated.

This would be a 3D view of the scene, as an example And this would be the 2D perspective, and the player will be able to jump from the small block to the large block without problem, which he couldn't in 3D.