Endless Grid, 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
Eighteen clues and a long chain: this board takes four rounds of checking, more than any other 10x10 except the finale. Five pieces are fixed at the start, including the tall 6 in the top-left corner and the patches in the top-right and bottom-right corners, and the middle fills in slowly from there. Watch the shape-only wide clue in the left half of row five, which can't be settled until the third round.