GOOD BITS: The art is magnificent, it is crazy impressive how Makoto Yukimura drew such detailed spacecraft before moving onto vikings. It's clear he understand what he's drawing as well, the pages detailing the propulsion system in spacesuits and the helmets etc. are quite detailed despite not being necessary for the plot. The characters and the growth they go through are fascinating, each character is wholely different from one another and they each change in meaningful ways. The story, while simple, is also interesting and involves a couple twists and turns which help make it interesting. The main story is simple but it provides roomfor growth and has a clear end in sight.

BAD BITS: There aren't many. My biggest complaint is that Yuri can be a bit underutilised, but he had his story in the first chapter and before the main plot begins, he doesn't have much more room to grow so the story doesn't have to focus on him.
That's really it apart from some nitpicky or personal things like the old Ukrainian woman not being translated, but it just becomes a positive when you can still understand the sentiment behind her words from the art alone.

TLDR: Amazing characters and world with amazing art.