“Only Venus spins “backwards”.”
Venus and Uranus spin backwards.
Uranus rotates mostly on its side. I don’t think you can count it either way. Its axis of rotation is more or less in the ecliptic (more so than Earth’s is perpendicular to it, by a factor of three). At one point in Uranus’ year the planet appears to rotate clockwise from the perspective of the Sun, and half a Uranus year later, it is rotating counter-clockwise. At the quarter-year points it is either rotating “up” or rotating “down”.