A WW2 battle tank pin would be ideal. Something like from the movie Fury.

Image the player/players with a tank that is slightly setback from the flippers. And a cannon in the same area (obviously above the tank) that shoots all the balls. The display would have a map with different missons to progress and to go to join new battles. As you destory tanks you could upgrade your armor, increase ammo (extra balls), earn rankings. You could even go heads up or team play online with other players. With an online ranking system. Even have monthly payouts to top players/teams.

Thoughts?