Note to all aspiring flashers
Watch this frame by frame and note how fast-moving objects are drawn in a blurred fashion, and also note how the animation doesn't have to be as smooth as you might think in order to look good. The blurring especially makes it look more realistic though. If you ever watch an old disney cartoon like aladdin you'll notice they do the same thing. You can pause a VHS and catch a frame where the character's eyes are drawn several times to fool the brain into thinking it saw them at several locations within the space of the instant. Anyways, interesting oldskool approach that works much better than straight "tweening", which tends to look like crap.