Normal sudoku rules apply. Shade some cells such that all shaded cells are orthogonally connected, and all unshaded cells are orthogonally connected, and no 2x2 area may be fully shaded or unshaded. Each cell in row 9 reveals how many shaded cells are in that column. Furthermore, in each column the shaded digits in that column, must increase in value, going from either top to bottom or bottom to top. Cells separated by a red dot sum up to 9. A digit on a circle has its value increased by 9.