For someone to enjoy this movie, they must set a very low bar for anime films. This was a glorified music video with a story written by someone with little regard for plausible character motivations, places zero importance on human rationality, no intention of creating a coherent plot, and without basic understanding of massive online games. The drive behind every characters' actions (main, supporting, and background) range from shallow to senseless. Everyone of them is a caricature of simple-minded humans whose only purpose in the film is to be a "plot" device. The movie places tremendous emphasis on visuals which was decent (not stunning) but every other aspect of the film suffers for it.
TL;DR: Artfully crafted pile of senseless garbage. Hated it.