I would say this kind of perspective works a lot better:
I would need to decide if i want a "Stage" at the bottom, but i think the sides and some of the top would match greatly for red theater cloth.
I like the style.
About the red curtain: No cloth modeling in Unity?
About the perspective: To transmit the feeling of looking into a box, you
need another, a more general, perspective projection, one that allows you to
view onto the projecting plane from an oblique angle. Such a projection is
called an oblique perspective projection. You may already have heard about it.
However, not all graphics packages allow for setting up such a projection out
of the box. In OpenGL for example one can use glFrustrum, whereas OpenGL's
gluPerspective won't do the trick, by setting up a bounding rectangle within
the view plane who's center does not align with the center of the view plane
coordinate system from which the center of projection is computed - depending
on the given viewing rectangle. Hence, the frustrum gets sheared. Another
approach some packages uses is by keeping the viewing rectangle fixed and by
varying the center of projection. But even if neither of these options are
available, if one knows the bounds of the viewing rectangle or the center of
projection and the viewing rectangle, one can construct kind of a shear matrix
that transforms the camera's view volume to have the desired effect. But then
camera space might not be accessible within some packages. In such a case a
shear matrix must be constructed in object space such that the transformation
to camera space gives the same result. So much about the theory.
I guess you can set up such an oblique projection matrix in Unity. If Unity is
modeled after OpenGL's perspective setup, you may take OpenGL's perspective
matrix used by glFrustrum. Direct3D does also have such a matrix. However you
arrive at it, once in place just either vary the view rectangle or the
perspective center of projection slightly to the left/right/bottom/top (while
in oblique mode, i.e. keeping the plane of projection fixed). This will
generate the desired effect, which is way cool! But if you want to make it
real stunning, couple the oblique projection with a head-tracking device (each
mobile phone has a camera). Then map the head's position to the center of
projection or modify the position of the view rectangle while in oblique mode.
Without any doubt, watching the theater that way will blow you straight out of
the water!