Both banks of drops are linked in multiball. Focus on upper playfield to quickly raise the drop value and collect decent points in mball.
Top lanes and ramp adds "PIN BALL" letters (i.e., bonus) in center of playfield.
Spelling "PIN BALL" lights special. When set to points, Special is worth 500k (big points; you can look at it as a 'Super Jackpot').
Completing top lanes, or 1 - 7 yellow targets, builds playfield bonus X. This value multiplies switch values in multiball.