x1 (abstract) is amusing/entertaining to x2 in property/aspect x3; x3 is what amuses x2 about x1.
Also: x1 occupies x2 pleasantly; x1 is fun for x2; x2 is amused by x1; x2 has fun (at) doing x1; x1 is an amusement/entertainment/game for x2. See also cinri, panka, xajmi for funny, kelci.