Is Up the least cowardly animated movie?

Aside from South Park. Basically, it doesn't hold back. It doesn't try to water itself down to appease the over-protective parents who complain about everything. It doesn't portray the world as a utopia full of rainbows and unicorns, it shows the world for what it really is.

Of course there's the first 10 minutes where Ellie has a miscarriage and later dies, and it also shows that people have money troubles and can't afford everything, but that's not all.

After Ellie dies, Carl doesn't instantly get over it, it actually shows him grieving for the rest of the movie. Not subtly either, he actually talks to Ellie, looks at photos of her, etc. But it's mostly shown in his personality, how he was extremely happy before, but after he's miserable.

The movie shows that being old doesn't always make you a wise man who always tells stories and gives advice, it often makes you grumpy, lonely and miserable.

When Carl hits that guy on the head with his cane, he's actually injured and bleeds, and Carl actually faces consequences.

There's the situation with Russel's parents and Phyllis, which they made a little ambiguous, but that's good. Basically, it shows that not all children have a big happy family.

The villain doesn't chase the heroes around with a tennis racket. He's a murderous psychopath, he shoots at them with a shotgun, tries to slice them with a sword, and dies at the end.

I could go on. It's mostly simply in the writing, how it portrays real human sadness, anger, love, etc throughout. It's very much an adult film.