Slide 3 shows a picture of Saturn. Saturn is spinning so rapidly, it is being flattened by centripetal force. The picture is an optical illusion. The planet is really spherical. Titan have about the same mass, Titan has an atmosphere, but Mercury doesn't.
Mercury rotates slower.
Mercury is a terrestrial planet. Mars started out closer to the asteroid belt, and therefore was subjected to more meteor collisions. Mars started out with less mass, and therefore couldn't hold onto its lighter gases. Saturn's rings extend to inside the planet's atmosphere. Saturn's rings are further from the planet than its outer-most moon.