What is Zero?
I found it funny really. I meet a hand full of people now who likes No Game No Life but refuse to watch No Game No Life Zero. In No Game No Life all conflicts must be settle with a game. The people who bet in the games can bet anything even their own existence. The main characters in the Anime are Sora and Shiro, a brother sister pair. In their own world they was NEETs who was known as (Blank), an online gaming group that never lose. A NEET is someone who is "Not in Education, Employment, or Training" The Movie, No Game No Life Zero focus 6000 years before the Anime. Before Tet became god and forced all conflicts to be settle with a game. It felt like the world was on the verge of destruction doing the entire movie. A lot less colorful then the Anime.
Why the hate?
No Game No Life had two main characters. These two people are human, and in fact from a different world. They wasn't around or even a tinkle in ... not sure how many greats grandfathers that would be. But it does have a spiritual doubles of the main two characters. So some people feel that it's just a large filler plot. But did you know that No Game No Life Zero is in fact canon? The movie is covering the sixth volume of the light novel. Now the anime does only cover the first 3 novels but as Zero is a Prequel it doesn't hurt putting it out of order.
While the Anime has Sora and Shiro, Zero has Riku and Shuvi, of which only Riku is human. Without the rules the game of gods Tet put in place Humans are hiding to survive. Most of the more advance technology is shown to be fueled by magic in this world. Humans not only can't use magic but can't even tell if it's being used, making them all but unable to fight back. Then enter Shuvi, an Ex-Machina who want to learn about the Human Heart. Looking at humans from her point of view cause her some issues. How is it possible for humans to not be extent, as they have nothing going for them she wonders. Her quest to understand this put her in contact with Riku.
The only other reason why people avoid the movie is because it isn't set with the same rules that No Game No Life Anime has. It isn't all about the games. It could be that's why they called it Zero, because of the Zero need for games? Although games are played it does not give the same feel. The movie helps expand the world of No Game No Life. Helping us understand parts of the world that the Anime hasn't covered yet but also help our understanding of how the world got to be how it is.
I will also say that I found Riku and Shuvi, while very similar to Sora and Shiro, to be there own Characters. If they was in the same timeline it would seem like lazy writing but while I have read some reincarnating theories about these pair but the entire story is told from the point of view of Tet telling Izuna. To quote the light novel, Izuna acted like she knew she was being tricked by the story, and even point out the main two was too much like Sora and Shiro. Doing the movie we see both Riku and Shuvi grow and change. Even more so then Sora and Shiro did doing the entire anime. Because this is Tet who told the story, we don't know if he changed it up some, if Izuna related them to the people she knew more then Tet did, or if Tet was after Sora and Shiro because they was somehow related.
If you haven't watch No Game No Life it's a very good anime. I would watch it before the movie but if you haven't watched the Movie then you really should do so as well. No Game No Life isn't a Hidden Gem simply because it's too well known. The show with it's odd rules is much different then other shows and should be given a chance by all. Although it does to push the envelope every chance it gets which understandable would push some away. But I'll mark this as a True Gem, Many who don't like the Premise would find something to love about this anime.