Interactive logos and graphics are another side of motion design. These designs are created in programs like Java, Flash AcionScript, etc. and they use code.
Changing over time: Change can occur on may levels in an animation. From color, to speed, position, rotation, shape, depth, transparency, and combining any of these variables together.
One thing that interest me very much so is text in motion. Keeping the word(s) legible is a key factor to the success of the text in motion.