Neat Assembly, a 6x6 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
Three corners are settled before you move: a tall 3 in the top-left, a 2x2 square in the top-right and a wide 4 along the bottom-right. The 6 near the top has nine ways to fit at first, but squeezed between those corners and the wide 3 below it, it ends up as a 3x2 block. Two more 6s and a second square fill in the lower half.