Fill all empty circles so that the numbers 1 to 4 (for 4x4 puzzles), 1 to 5 (for 5x5 puzzles) etc. appear exactly once in each row, column and chain (More here)

Paint squares as you solve the puzzle and discover a hidden pixel-art picture (More here)

Find the way clues are linked, paint the paths and discover a hidden pixel-art picture (More here)