Logic Masters Deutschland e.V.

Rules:

Draw two loops. Each loop is orthogonal, non-intersecting, and goes through the centers of some cells. Each loop passes through every region exactly once. The two loops may not overlap each other nor turn at a shared cell; however, they may intersect perpendicularly.

Within a region, one loop passes through all moons and no suns, while the other loop passes through all suns and no moons. A loop cannot pass through the same type of clue (sun versus moon) in two consecutively visited regions.

Solve online:

Penpa+ (Note: It is recommended you go to settings and turn on "Any color can match green line/edge in solution". That way, each loop can be a different color and answer check will still work.)

SudokuPad (Note: This version does not have answer check.)