This is a Fillomino puzzle where every polyomino is required to be nonrectangular (which also bans squares). Write a number in every empty cell so that every group of cells with the same number that is connected through its edges is a shape that’s not a rectangle with that number of cells.
Fillomino-Fillia 2 is coming! Anyway I don’t know how to judge difficulty but this is probably terrible practice. I should try a Skyscrapers if I can keep pretending USH homework doesn’t exist which I probably shouldn’t.