Mars is a sci-fi manga that tackles the themes of human aggression heavily inspired by Japanese post-World War II fears over weapons of mass-destruction and dialogue of the time. In addition to these worries about atrocity committed by mankind against itself is a clear focus on man's treatment of the environment around them and of animals. It is not so sympathetic to humanity. The story itself is a tale of aliens having set guardians to watch over the Earth and to destroy it in the event humanity reaches the point where their weapons get sent into space and could wage war and become aggressors anddestroyers of worlds across the universe.

It is bleak and apocalyptic with elements akin to disaster films as certainly such a scenario as plays out would be. I enjoyed it. It's a very quick read. Can be read in one sitting. Very good.

The manga artist Mitsuteru Yokoyama is noted as being influential in multiple genres like mecha, battle manga, and literary adaptations apparently. The characterizations at least for Mars seem to be lighter and more simplistic and apparently this is a common thread for his work and with a larger focus on the bigger events and concepts of these stories. From what I read while Tezuka established the technical style aspects of manga, Yokoyama established format of different types of stories and genres and was apparently very permissive in letting adaptations be changed from his source material.

The mangaka of Akira cites him as a major influence and I can see it. I'm almost surprised by how low Mars' rating is considering the rating inflation on this site. It's not the most complex story or narrative but it's a good, quick and compelling read. It also sets the stage for many works that would come after it whether in mecha or other sci-fi tales.

Low-commitment and pretty good once it ramps up. I'd give it a read if any of the above interests you.