Much better than sequels usually are, this character-driven effort emotionally engages right from the start; leading to a finale that is hard to forget and deeply disturbing. Much like a Jacobean revenge tragedy, the downbeat ending is inevitable and tear-jerking - but without cheating the audience of its tears with fake or cloying sentimentality.
Along the way there is much satire of a paranoid and distinctly-violent White culture that is both impressed by talking apes, yet horrified by the implication that by the year 3955 humans will no longer dominate the Earth and control its resources for its sole use.
Everyone is good in this movie and the writing is first rate, except for the fact that the nature of the Western culture satirised is never explained nor elucidated.