Idk ya'll, I think we know better than to think that R-rated=great movie.
Look how that worked out for Hellboy: people on old circles of mine used to claim that the Del Toro movies were softer than the source material, and yet to this day both are still better than the so called "mature" reboots.
Also, if you handle the age rating properly, you can get away with quite some stuff. The Batman for example was PG 13 in various places and showed tons of heavy themes. And Transformers One/Rise Of The TMNT The Movie are family movies and yet have some visually strong scenes.
And of course, we have the classic example of Wind Waker having a very well-thought out story even with its artstyle.