For example, if the Earth was four-dimensional, it wouldn't have two poles and an equator; instead, it might have two equators, both orthogonal and equidistant to each other. And the 4D Moon's orbit around the 4D Earth (never mind the stability of orbits in four dimensions in the first place) could be at a constant 90° angle to the Earth's orbit around the Sun. And I won't even try to imagine what a 4D galaxy would look like, although it definitely wouldn't be a flattened disc like our own Milky Way.