)
Final Fantasy: Spirits was alright, but nowadays it's CGI while impressive for the time is seen as "uncanney-valley," and "creepy" nowadays, as "realistic" style CGI just doesn't sit well with those whom prefer more stylized animation, and the human eye can spot uncanny-valley easily.
Kinda a shame, because I like seeing other animation styles besides the usual Pixar/Dreamworks style.
But yeah, "mature, but not too mature" animated movies are hard to come by, as TV & Hollywood's idea of "maturity" is teenager poopy/sex humor. And while that's ok sometimes, it's hard to find "mature" animation that focuses more on action/adventure/seriousness. (Aside from anime, and DC animated "straight to video" movies.)