By classic 2D, I mean something like Pac-man or Asteroids - actual flat 2D, as opposed to the Unity 2D tutorial, which uses 3D objects with their movements constrained to 2 dimensions.
I'm planning to make a demo game, and my first thought was to to use GUITextures. However, I have discovered that they are fairly limited (no renderer or use of shaders, for instance).
The other option (that I know of) is to use 3D objects with an orthographic camera and constrain the object motions to 2D. (Which is how the Buzz tutorials work, for example). That would work, and I guess performance isn't an issue, but it just bothers me to think of using a Cube Mesh object with a Pac-man Texture painted on the side - it seems like overkill. :)
Are those the only two choices for representing a flat game, or is there another way? And are GUITextures up to the task, or should I just bite the bullet and use Meshes?