Steven once is naked on screen in the episode "Frybo"

In "Keystone Motel", Ruby kisses Sapphire on the neck.

Infrequent innuendos throughout the show, some being worse than others.

"Meat Beat Mania," an Arcade game in the episode "Arcade Mania" may be an adult joke. Along with the line, "Shake the meat to the beat"

The fight scenes in the show involve magical fantasy weapons or just weapons in general. However, most of them are utilized to harm gems rather than humans.

There is some crushing to death of minor characters. At one point, a Zircon lawyer gem is poofed after being crushed to death; Peridot steps down on a flask robonoid at another point, slowly crushing it to death and smiling, which upsets Steven.

Steven goes around with a black eye in one episode after a fight. This upsets his father and Connie.

Some mild violent dialogue, for example Jamie the mailman's love poem to Garnet, which features lines about his arteries and his heart being torn out.

Varies depending on the episode. Lots of episodes don't have much/any action. Lots of episodes do contain fight scenes, sometimes extended fight scenes. These can include punches, kicks, swords, and some sci-fi/magical weapons, sometimes against magical beasts, but main or side characters fight each other sometimes. In season 4 there was very little violence.

There is very little blood - only red cuts are shown, and even then only about two times in the whole show - usually we see black scratches when a character gets beat up.

Some violence can be surprising. In one episode Pearl is suddenly impaled with a sword (but is fine at the end of the episode).

Most of the fight scenes involve "magical" beasts.

Malachite and Alexandrite have a large battle using various weapons and attacks, and some punching. The fight lasts almost four minutes. During this fight, several sentient watermelons are crushed to pieces onscreen.

A disturbing concept in this series (first seen in season 2) is the forced fusions - gems that have been shattered and forced together.

Two uses of "suck" in the episode "Steven vs. Amethyst."

Everything is clean, but there some mild name calling.

Lapis and Jasper have quite possibly the most realistic depiction of an abusive relationship ever shown on kid's TV. It's not even hidden - it's straight-up abusive - and is resolved in the end with violence.

Some scenes are extremely trippy and confusing, including an Uncle Grandpa crossover, Pearl dreaming of Rose turning into Greg before vomiting a slice of pizza at random, and bizarre colors and flashing lights, which may bother younger viewers.

The Kindergarten, especially the abandoned gem injectors (which resemble viruses) may upset and frighten some viewers.

Even Steven Universe is similar to Adventure Time and cartoon, this show contains serious issues/dark theme in Cartoon Network show. This could pushed the TV-PG.

Whilst not usually scary, Steven Universe can become very intense and mature for a kid's show.

Darker and deeper themes are explored in this show, including consent, abusive relationships, war, murder, genocide, depression, anxiety, grief, bereavement, and PTSD.

We find out very early on (2nd episode) that Steven's mother, Rose Quartz, essentially died to create Steven. This is brought up over and over again throughout the series. The effect this has had on the other gems is shown, especially Pearl who was hopelessly in love with Rose Quartz for millennia.

The entire climax of Bismuth is very intense.

Cat Fingers (6th episode of the show) is infamous for the part where Steven accidentally turns himself into a cat monster, with lots of body horror shown in explicit detail, especially for a kids show. Both children and even adults may be frightening by this scene. In fact, this episode is so unsettling that Estelle, the voice of Garnet, stated in an interview that this episode is "the least kid-friendly episode of season 1A", which says it all.

Frybo might frighten children.

The whole forced fusion concept is quite disturbing.

It should be noted that in non-US airings of this show, some of the less child-friendly content in this show (all categories) has been removed. (For example, UK airings have censored many episodes of the show).

It should be known that Homeworld is a very totalitarian society that immediately kills any gem that doesn't fit in without batting an eye. This is shown as a stark contrast to Earth, which is open and accepting of defects and differences, and embraces them.