First, dont add anything except gui to guiNode.
-You can make another node for you level , called levelNode (no surprise). Add your character and other stuff in that node, attach it to rootNode.
- You can make the main camera ortho How do I make my camera go in ortho mode? - #13 by Momoko_Fan
- DONT Make your levelNode scroll, or the camera scroll (move) as your main character go. You can make a CameraControl for that purpose
Cheers,