Theme: Squeeze Play.
Answer String: For each cell in the marked rows/columns, enter the area of the polyomino it belongs to. Start with the 7th row, followed by a comma, followed by the 9th column.
Time Standards (highlight to view): Grandmaster = 4:30, Master = 9:00, Expert = 18:00
Note: Advice on solving this puzzle has now been posted in “Ask Dr. Sudoku #10“