Wauwatosa, WI
What exactly defines an upper playfield? I tend to think of things with at least one flipper, so things like the roll overs for LOTR don't count. They have a purpose for what they are doing, but the goal isn't for you to be able to control the ball up there.
To me, a good upper playfield is something that has a purpose and is deep enough on it's own. A lot of playfields that people have named I find myself either able to keep the ball up there for a long time doing not much or are just too simple.
Having said that, the winner to me is Popeye. Seriously. Not just does the upper playfield contain two flippers, but the shots that you make are interactive with the DMD on the backbox and change based on what you just did. It makes it a different sort of challenge.
Toronto, ON
