An instant roadblock in that is the fact that the rights to the original dub cast couldn't be obtained for whatever reason, so I'm immediately getting partially different identities from the characters that lowers my built up affection for them that'd make me more sympathetic to this movie's weaknesses. I adapted quickly anyway since you're focusing on reading subtitles, but since the Persona 4 anime got a dub this is disappointing nonetheless and regardless of the excuses feels like more neglectful behavior towards Persona 3. The most interesting thing about the movie compared to the game's story is that the main character, who was previously a near blank slate for the player to insert themselves in, has been made into a more specific character. The way they went about this was actually quite clever. For a while, people insisted that P3's MC's personality was reflected by the alternative third response in each dialogue option. You typically had two different but tactful responses and then a third one which was usually humorous and sarcastic. People joked for a long time that the Persona 3 MC was secretly an asshole because of this consistent option, and surprisingly the writers of the movies adopted that personality for him. What's doubly clever though is how this bitter, sarcastic personality complements a new distant side to the MC's personality that gives an excuse for him to have a low amount of dialogue and personal input replicates how little he actually speaks in the game. The writers of the movies had to give the MC some agency now that the player wasn't choosing it, but they compromised between his representation in the games through possible dialogue responses and also retained some of his anonymity and non-involvement while making it all feel in-character.
Well that's pretty intelligent, but the rest? It's all Persona 3 but weaker. Only the most minimal of new transitional scenes and original content are allowed because the movie's plot is already struggling to hit the same emotional stride as the game. The movie's predicted focus on only the story's plot climaxes like the full moon battles and party member introductions ensures that each has less impact because a huge chunk of the flavor dialogue inbetween these segments that would allow you to understand the characters and empathize with them in times of crisis is cut down considerably. If nothing else this provides me something to point at when people say nothing happened during Persona 3 between full moons. Watch the movie cut down all of the so-called "fluff" and realize how insignificant all plot development is when it doesn't have proper emotional payoff behind it. Just because Persona 3 wasn't constantly concerned with advancing the story of the Shadows doesn't mean every other scene wasn't deliberate build and progression, namely in that aforementioned flavor text that's now missing that would've detailed the setting and characters into diverse, real-life parallels that were actually worth caring about and saving. Every little bit that made these aspects more understandable and relatable could be considered plot development, because as we can now literally see, the plot isn't much without them.
The movie is forcing the plot along so much that there's not enough scenes that show the characters interacting or influencing each other without some forced goal on their minds. The movie covers the first three full moons (including the intro) which would've taken several times the movie's length to reach in-game, and even when you cut out Tartarus's play time (which is still some player/character bonding) it's still a large chunk of time spent on world building that's now missing. There's so much action and plot exposition in Persona 3 that it feels soulless compared to the games, which can be a bit ironic since many people wanted that focus. If someone hadn't played the games before watching this for whatever reason, I doubt anything in the movie's set-up would've been enough to force them to care. As someone who has played the games and is trying to watch this as a separate experience in order to justify its existence, I also find it hard to care because when isolated from the knowledge of the game I'm using to fill in the missing blanks it's still an amateurishly constructed movie as stated earlier.
When you get right down to it, the most enjoyable thing about the Persona 3 movie as someone who's already experienced the story in a better way is that it at least gives us a new visual angle to see Persona 3's world and story from. The animation quality is great, and seeing Shigenori Soejima's phenomenal art transitioned perfectly to animation is always a treat, even though it still feels very familiar in how accurately copied it is. The surreal Dark Hour design is given a lot of attention without any gameplay to focus on and being in the background of several frames, and though the plot's emotional strength is missing the emotions to come from the game's somber sense of tone are all perfectly on-point. The lighting and color design is still mellow yet pulsing with curious mysteries, and locations like Iwatodai Dorm instantly evoke the same atmosphere as they do in-game. The reuse of Shoji Meguro's game soundtrack works just as well in the animated scenes, although the extended sections of old songs are nothing to write home about even though the effort's appreciated.
Does this adaptation do the video game version of Persona 3 justice? I don't know whether to say yes or no. No, because the game is a superior format to experience everything that is Persona 3. Yes, because with the time limitations they did about the best they could. But if this is the best they could do, then maybe the real answer is that an adaptation just wasn't a good idea in the first place. If nobody needs it, I don't see the point of making it and insisting it as a genuine complement to the game, but I guess it would seem pointless to me when I'm not the one making millions of yen in profits. I think I would've taken a fourth game version of Persona 3 over this movie.
