Some of the humor (references to body odor/picking noses and eating it) was a bit of a different tone than I remember from older films, but it certainly wasn't anything I'd call 'grown up'
I do think it's a movie that adults can enjoy without kids. It's probably my favorite Disney film of the past several years. But as far as I can tell, kids love it too, so I think they succeeded at making this one appeal to whole families.