Cell Blocks

Each clue's shape is fixed by its divisor pairs: a highly composite number like 24 has eight possible rectangles to choose from, a prime just one — that divisor count is the whole difficulty dial.

This board can also run Fillomino, the same grid without the rectangle rule, where regions take any shape.

RULES

• Each block holds exactly one number — its area, in cells.

CONTROLS

• Tap two opposite corners, or drag, to draw a rectangle. Tap a block to remove it.
• Arrow keys move the cursor; hold shift and arrow to size a block, then press enter to draw it — enter on a drawn block removes it, escape cancels a part-set block.