Here are some map ideas that I think would make a great addition to the game:
1) Bumper cars/Dodge-ems at the theme park/fun fair. Eliminate players by pushing them out of the arena.
2) Giant wrestling ring with varied weapons, elimination over the top rope game type.
3) Pirate ships - each team tries to board the opposing teams ships to steal their treasures and bring them back to their own before the time runs out.
4) Basketball - 4v4
5) Food fight at a 60's diner