2D Puzzle in 3D Game First Person

Hi,

I need a tutorial for include a 2D Puzzle in a mobile 3D Game First Person. When the character enters in a trigger area, I hide the mobile controls, enable the slide touch capacity and show the 2D puzzle, a slide memory card game for example. After the resolution, I hide the puzzle, disable the touch, show the mobile controls and the character continues the navigation. Anybody can help me?

Thanks,
Alessandro