Looking at the Baby Pac playfield, it seems chunky enough that you could get away with assigning a collision angle to every character cell of the playfield. Assuming you can do per-pixel collision of the ball against the playfield, that would get you playfield physics decently enough. As for the flippers, you could use the same approach for when they're full down and full up, but for the actual flipping, a pre-computed table of angle-velocity modifiers for each horizontal pixel of the flipper might be the way to go.