The World of Mario: As a Play
This isn't an actual play, but it is set up to look like one. This Mario Cosplay was originally submitted to Kotaku for the Halloween Contest and has since then set up their own website.
I encourage you to check it out, the costumes and backdrops are wonderfully done and the characters set expressive poses. The best part is definitely when Mario opens fire on a Shy Guy Village by throwing fireballs at the villagers.
Link (via Kotaku)