Quoted from Rum-Z:
No lower playfield, just a big Herman Munster face in its place (ala the first AC/DC Pro), LOL... hopefully Stern doesn't do that. But I could see it.
The lower playfield in acdc doesn’t really do anything, kind of weak I think, more of a diversion from the game. If you could play both the lower pf and upper pf at the same time and have rules associated it with them, like combos or something, then I think it could be cool.