Let me just start by saying I am not a fan of One Piece. A lot of people love it, but I can't get into it even after I've tried a few times, it's gone on way too long and I find a lot of aspects of it personally pretty off-putting and stereotypical. But I have a strange relationship with it; although I'm not a fan, I can understand why so many other people are and kind of wonder sometimes why I'm not.
I was referred to this movie by a YouTube video about One Piece's appeal and figured I'd try it out even if I don't like the series, and I've gotta say, I actually liked it.
The first half still had some of the aforementioned off-putting aspects, like the stupidity of Luffy, the over-the-top quarrel between Sanji and Zoro, and some of it still having plenty of Shonen cliches and slapstick comedy. But over time, it changed drastically. It changed from the carefree insanity of the anime series to a more somber tone. Little by little, I found myself actually getting intrigued, and the plot actually felt pretty interesting and I liked the difference in storytelling from the manga where it actually let it's audience think as opposed to just having the plot laid bare before them.
A lot of One Piece fans may have found the sudden change to a dark tone to be out of place, and while I kind of agree with that, I also enjoyed it. As I've said, the general tone of One Piece really turned me off, but this movie actually had a tone that kept me intrigued, especially in the second half. And some of the new characters were actually pretty interesting and the main characters got different characterizations as time went on. The villain himself might've been a little over the top, but honestly, the conflict he created was fun to watch.
There were some parts I still didn't like though, like the villain himself who had motivation for his actions, but it didn't completely make sense. And for the second half, Luffy (the character I found most annoying) had screen time dominance. I think this could've been a little better if it wasn't a property of One Piece, but an original movie instead.
That aside, though, the animation is gorgeous. The characters got some slight redesigns that look pretty cool, the movement is very fluid, especially in fight scenes, and there's few if any still shots or stiff movements that are common in tv anime. Also, it seems to have a similar animation style at times to Studio Ghibli. So it's pretty much a combination of Studio Ghibli and a really high budget anime.
All in all, it's not a perfect movie by any means, I think it would've been better if it was an original property or something rather than a spin-off of One Piece, especially considering director Mamoru Hosoda's talent in the field of animation. But still, I think it was interesting, if One Piece in general took a similar style of tone, I might like it better. The first half might've still been a little off-putting to me, but the second half was awesome.