In the most general sense, Sword Art Online the Movie -Progressive- Aria of a Starless Night is a retelling of a story we have already seen before—namely the first and second episodes of 2013's Sword Art Online TV anime. It covers the story from the time just before the launch of the VR game up through the battle against the first-floor boss. However, that doesn't mean that there isn't a ton of new content.

The biggest and most obvious difference between the TV episodes and this film is the change in protagonist from Kirito to Asuna. In fact, other than a few flashes here and there, Kirito doesn't even really properly appear until the film's second half. This allows the film to spend a hefty amount of time showing us Asuna as we've never seen her before.

When we are first introduced to Asuna in the TV anime, she is a socially isolated, hooded figure who is single-mindedly focused on clearing the game. The first half of the film is the story of how she gets to this point. Not only do we see her daily life in the real world, but also how she adapts to the death game she finds herself trapped in. Her progression from a pampered, innocent girl to a goal-oriented loner is told well—largely thanks to the inclusion of Misumi. Having a friend teach her the basics makes Asuna's survival up to when she meets Kirito far more believable. Of course, this also brings us to the elephant in the room: the existence of Misumi herself.

Misumi—known as “Mito” inside the death game—is a new character to the Sword Art Online franchise. She is not seen in either the original novels or the anime—she's not even featured in the Progressive novels on which the back half of this film is largely based. And while her inclusion makes sense logically and thematically, the fact remains that the vast majority of viewers of this film will have seen the original Sword Art Online and know that by the time Asuna encounters Kirito, Misumi is no longer in the picture. And this being the story of people trapped in a death game, it's not hard to guess at where Misumi and Asuna's arc is headed.

Luckily, the film seems aware of this fact and plays around with the viewers' expectations. While it's true Asuna has to be alone by the time she encounters Kirito, that doesn't mean that the film takes the easiest or most obvious route to get there. In fact, the story becomes much more interesting and relatable by taking the unexpected path—connecting the two halves of the film into a singular, cohesive whole as it does so.

The second half of the film is largely a retelling of the events of the TV anime's second episode—i.e., detailing the first team-up between Kirito and Asuna. While certain scenes are repeated (though notably now experienced from Asuna's viewpoint), there are a good number of newly-animated scenes taken directly from the Progressive novels as well. It's only in the final action climax where the film directly contradicts the source material and previous adaptations in any major way. And while making such blatant changes is risky in a well-established franchise, doing so makes the film a better stand-alone work.

Visually, the film looks great. From the sweeping vistas of Aincrad's first floor to the chaotic and flashy battle scenes, the animation looks crystal clear. It's easily on par with the previous feature film and the best the various TV anime have to offer. As for the aural side of things, many of the established soundtracks return as expected—most obviously the commonly used action theme. Interestingly, the film tends to use it only in scenes where Kirito is present—leaving Asuna's own distinct action theme to shine through for most of the story.

All in all, while Sword Art Online the Movie -Progressive- Aria of a Starless Night doesn't come close to reaching the heights of the Sword Art Online story, it is nonetheless a solid introduction to Asuna that details her first steps down the path to becoming the charismatic leader and badass swordswoman we know her to be. Likewise, by seeing the story almost exclusively through Asuna's eyes, the relationship between Asuna and Kirito gets put in a new light that adds new context to scenes we've already seen before. But best of all, it sets the stage for future never-before-animated Progressive tales—and more life and death adventure in the floating castle of Aincrad is never a bad thing.