Excellent. Several timeless, universal contrasting themes regarding humanity, connecting primitive man to today. Any viewer with basic film literary skills to recognize themes, symbolism and allegory will surely notice these, including the ending. The writing and characters are very good and represent these elments well. There are complex characters (3 initial tribe outsiders, 2 tribes) to represent the thematics with diverse human moments, along with unique and artistic direction, editing, sound design.

There are good and bad characters, light and dark, brutality and glimmers of good just like in real life, such a likely reflective of thousands of years ago to today. Many WWII films or modern history with them same or far worse brutality and social collectivism (ie. Nazism, socialist and communist genocides or in dictatorships in recent history, as real true examples) pale in context and carnage and brutality what is rationally shown here for obvious story of primitive man at an early stage.

It is pure fantasy to conjure an image of peaceful tribes without war or vying for power as seen here. You even have characters that fall outside these collectivist groups, which is more than any Hollywood movie today could or would show today (politically or otherwise in writing or with the same craft in direction, editing or original artistically superior soundtrack).

Given the subject matter, genre content, time period, context this film is more extreme and realistic than fantasy or fluff.

If you want Hollywood with Dolby sound, generic soundtrack, clean showered properly groomed media celebrity stars and mindless, theme-less safe entertainment movie, maybe Master of the World might not be for you.

If like a film with synth, ambient original soundtrack, creative artistic choices, editing, bold choices to reflect a gritty dark realism, good cinematography, characters, deeper themes, subject matter and even allegory than this might indeed be for you.

Not a mindless movie but a thought-provoking one requiring some semblance of intelligence at least a hair above that of a primitive.