Bring both Sun and Moon home to their matching rings. One input, two characters.
If a character hits a wall or the edge, only that one is blocked. The other keeps going. That is how you break the symmetry and reach asymmetric goals.
If Sun and Moon would land on the same cell, or pass through each other, neither moves.
Both characters must be on their own goal at the same time. The level then advances. Sixteen puzzles in this run.