The art style is very rough and dirty, character designs are even inconsistent. But the art truly shines in those artificial landscapes. If you're looking for character-driven stories or designs look elsewhere.
The actual story is pretty straight forward, but you stay for the journey. Similar to The Hobbit, this is a story about a guy (and his occasional party) walking the path towards a very straightforward goal, finding something.
I read the Master Edition which has 6 volumes with bigger pages and the last 2 volumes were my least favorite. Suddenly it all becomes about fighting and the most important thing of all, reaching the goal, takes place on only a couple of pages. The issue with the fighting is that because the art style is very rough, it can be hard to tell what is happening to whom. Some fight scenes I had to carefully indirect in order to decipher them.
In the end, this is a must read for any visual novel fan. The story telling is done in such a different way that is a great study case for a visual novels (comics, manga, etc) can be done in a radically different way than the mainstream.
Still, for me this falls short of other masterpieces (Berserk comes to mind), mainly for those last two volumes. In the end, the graviton gun wielding artificial and immortal super human will win and there are little to no stakes.
