The hand-painted backgrounds of AKIRA (1988) are absolutely insane.
Neo-Tokyo was built with an almost obsessive level of detail. Thousands of windows, signs, cables, buildings and tiny architectural elements were painted by hand, with some backgrounds containing incredible detail that appears on screen for only seconds.
One background from the film was so densely painted that collectors later discovered it occupied barely a quarter-inch of the finished frame. The artists still rendered all of it.
AKIRA had 2,212 shots, around 160,000 individual images and 327 colors, 50 of them created specifically for the film. Even nearly 40 years later, Neo-Tokyo still looks like a city nobody could have possibly hand-drawn.