> To play in Expert mode (with no stop indicators or arrows to guide you), press and hold L+R+Start after the Mode Selection screen.  The word "Expert" should appear at the bottom left corner of the Character Select screen.
(courtesy: GameFan)

> Plug a controller into controller port 3, then press the Start button on that controller after you started a game in Original or Arcade mode.  You can toggle to a first-person view by pressing B (switch back to normal view with A), get an alternate viewing angle with Y, or tap X (5x) to bring up a speedometer display.
(courtesy: DC-IGN)