Using Blender to create levels and importing into Unity question

Has anyone created an entire 3D level in Blender and imported into Unity and then repeat process for each level and saved the "scenes" in Unity?

Trying to find best way to mix my pixel art images into a 3D environment (for a 2.5 beat em up style game). I will create 3D walls and platforms to collide with and use my pixel art to shade/texture the models...except for the backdrops/grounds as they can remain 2D with colliders attached to them.

If so, what has been your best way of setting things up...say a level like 1280x280 pixel level?

Thanks...some tutorials don't really cover this unless I'm not using proper search words. Thanks

 

Ive done this with 3d levels, and currently doing various experiments with a similar 2d workflow, I don't think I've had any hang ups. save the level in your assets folder, drag it into your current scene, add a collider, and you should be good to go. Are there any specific problems happening?