Steel Lattice, a 10x10 Patches puzzle
Arrow keys move. Enter starts a rectangle; arrows resize it; Enter places it. Escape cancels. Delete removes a patch. Control or Command Z undoes.
About this board
Half the clues show only a shape, but a 25 in the bottom-left anchors everything: it can only be a 5x5 block, and it is fixed from the start. Above and beside it the board becomes a lattice of long beams: an eight-cell strip across the top, a seven-cell column down the middle, and a 2x5 block in the bottom-right that settles in the second round. Several beams are placed only by ruling out positions that would strand a neighbour.