This movie had big shoes to fill. After all,the novel is a really strong work of sci-fi, and it would be worrying if the anime would join the ranks of the Edge of Tomorrow live action as a really bad adaptation of that novel. It succeeded in doing so. The Visuals are gorgeous. The distinction between the alien and the human elements are perfect. The VA, despite being composed of a lot of newcomers, was really compelling. The pacing is set correctly, while conveying properly the frustration of the loops Now, to address the elephant in the room, the story is a retelling of the novel, with some massivechanges. However every new element fits. The alien design and behaviour, the way the society functions... someone who read the novel will agree that it fits perfectly with the novel's explanation of the alien behaviour.
I know this was the director's first feature length, and i wish him all the best in future endeavours.