The Last Ninja ran at resolution 160x200, with effectively 2-bit color for graphic assets. It had amazing animations for that level of detail, but all the variety of the graphics could not take too much RAM even if it wanted to.
The quest for photorealistic "movie-like" rendering which requires colossal amounts of RAM and compute feels like a dead end to me. I much appreciate the expressly unrealistic graphics of titles like Monument Valley.
160x200x2 still comes to 8 kB for a full-screen bitmap. So those 40 kB would allow for just five full screens worth of graphics/frames if stored naively. I'd say that still required some very clever programming to get that amount of scenery and animation in there, along with all the music and code.
There's a reason why only few games of that time felt as mind-blowing as The Last Ninja. Even getting a basic text adventure or Pac-Man clone in those machines took some skill, but with a game like The Last Ninja, I think a lot of devs wouldn't even have known where to start to make something like it possible.
The quest for photorealistic "movie-like" rendering which requires colossal amounts of RAM and compute feels like a dead end to me. I much appreciate the expressly unrealistic graphics of titles like Monument Valley.