This is a faithful adaptation of the manga, so both the manga and the film suffer from the same problem. I really think there needs to be more debate as to whether anime adaptations should be as accurate as possible or if they should try to improve upon the source material. In many cases, these alterations are disliked or questionable as to whether or not they were warranted, or they're just hatchet jobs due to time constraints. In this case, I think the author and the anime studio should have gotten together to expand upon this work, and make it into a slightly longer OVA series. It's sad to see that the weaknesses of a manga are adhered to when they could be improved upon... honestly, this would probably be closer to a dead-average rating of 5 if I weren't already invested in the chemistry and charisma of the three main characters.
First, I'll start with what the adaptation does well: Technical aspects are great. The visuals are similar to the original series, but the animation gets a boost at several points, especially during the fight scenes with Bondrewd and the "Dark Reg" segments. The opening 10-15 minutes before they reach Bondrewd's facility is very similar to the show and has a wonderful dark fantasy atmosphere. Same kind of character interaction, and the monster feasting scene is endearing. The sound and music all fit quite well, and the ending credits are handled in a fantastic manner that creates a massive sense of scale.
Then we get to Bondrewd's facility, and this is probably the most claustrophobic and drab setting of the entire series. The exterior and some of the more detailed interior shots are striking, but most of the interiors consist of bland, gray corridors and empty rooms. Even the textures tend to be blander than bland. I believe this movie also had a lot more awkwardly placed CGI then the series ever did. Whereas there's a sense of the unknown and a more dynamic mood in most of the series' settings, everything here feels so linear. There's no time for world building or much of anything else.
It's all rushed. We're strung along from one event to the next with no sense of rhythm. Rushed relationship-building with Prushka (Bondrewd's "daughter"), a couple crucial scenes between Bondrewd and Nanashi, to heavy-hitter sakuga action. It feels just like one of those One Piece movies where you're introduced to a few disposable good guys no one cares about and a powerful main antagonist; i.e., its sole purpose is for flashy key animation and money. Fortunately, this film does have good writing and characters, and Bondrewd is an excellent antagonist, they're just not given the proper room to breathe.
Prushka doesn't really seem like a bad character, but she is expected to bond with the group--primarily Riko--far too fast, and they don't really DO anything together. Some of the scenes between Riko and Prushka are shown out of sequence, but this just doesn't work, because we're given this small amount of development AFTER the point where we're questioning why Prushka was given so little time, and it's just not enough, anyway. There are also some flashbacks late into the movie depicting Prushka's earlier childhood. It's still not enough and feels a bit tacked on.
What would have made more sense would have been having Prushka pair up with the trio to go outside of the facility or even somewhere within the interior of the facility (it looks a lot like a city in the middle) for a relatively short journey. Part of the plot involves Prushka loving Bondrewd as a father figure and having positive experiences for specific reasons, so it would have made perfect sense for him to also have her bond with friends. I'm pretty sure that was part of Bondrewd's plan here, but it wasn't fully exploited. This would have also had the dual purpose of making the fifth layer not seem so entirely dead. As it's depicted here, we just get a frozen wasteland and a mostly bland facility. There's a lot you could do to liven the environment up a bit, and still have that sense of barrenness.
There's a great movie and story to be found here, it's just that the source material was flawed in the first place. It's really strange that the first and second season bookending the movie feel so much different in pacing. Dawn of the Deep Soul is like a short trek into a deep, dark chasm between the two; one that had a lot of the right elements, but we weren't given ample opportunity to fully plumb the depths.
