It tells the coming-of-age story of a young boy, Steven Universe (Zach Callison), who lives with the Crystal Gems—magical, mineral-based aliens named Garnet (Estelle), Amethyst (Michaela Dietz) and Pearl (Deedee Magno Hall)—in the fictional town of Beach City.

Animation was handled by Korean studios Sunmin Image Pictures and Rough Draft Korea, while the music composed by Aivi & Surasshu became an integral part of the series identity.

In the third season, Lapis decides to reside on Earth with Peridot, Jasper is defeated and captured, and Steven learns that his mother assassinated Pink Diamond, one of the Gem homeworld's leaders.

As he wrestles with his conflicted feelings about that, Pink’s counterparts Blue and Yellow Diamond begin to turn their attention back to Earth; the fourth season ends with Steven taken to the Gem homeworld to stand trial for his mother's crimes.

Some artists who had worked on the special, such as colorist Tiffany Ford and art directors Kevin Dart, Ellie Michalka and Jasmin Lai, were later invited to join the Steven Universe team.

[20] Before a production team had been appointed, Sugar tried to alter elements of the show's plot and developed the character's identity so her crew would have the creative freedom to implement their own ideas, like she did when she worked for Adventure Time.

[44] Sugar wanted the series to focus on comedy and positivity before exploring controversial subjects involving the main characters, thinking it was "more honest" to begin the show with happiness instead of action or drama.

[47] According to Ben Levin, drafting a season of Steven Universe was like a "jigsaw puzzle" because the writing team must assemble a number of plot ideas, which were discarded if they do not benefit character growth.

[55] Art director Elle Michalka said the backgrounds' artistic style was inspired by French post-impressionist painter Paul Cézanne, whose apparent lack of focus belied detail and specificity.

[49][79] The series also expresses the importance of acceptance,[80][81] and explores relationships, LGBTQ identity, body shapes and "hues of skin in a colorful sci-fi magic display of diversity", quoted by Sugar.

[93] Sugar told Vanity Fair in March 2021 that she had been determined to make "queer couples and narratives" integral to the story in ways that are "impossible to censor," and had to fight internally for the representation.

Club attributed the effect to Steven Universe's unusual—for a youth cartoon—adherence to an overarching plot, which can generate "massive swells of online interest"—similar to the release of full seasons of adult TV series—which are "crucial to a network's vitality in an increasingly internet-based television world".

[116] The second volume contains five minisodes that show Steven cooking, performing karaoke, reacting to an episode of his favorite cartoon, video chatting with Lapis and Peridot, and playing a new song.

The website's critical consensus for season five reads "Having blossomed into a sophisticated mythology with a deeply moving subtext, Steven Universe remains a sparkling entertainment and perfect introduction to LGBTQ representation for children.

[174] Critics have praised the "breathtaking beauty",[175] "intriguing, immersive environments"[176] and "loveably goofy aesthetic"[173] of Steven Universe's art, writing highly of its distinctive, soft pastel backgrounds[176] and its "gorgeous, expressive, clean animation".

[177] Reviewers also enjoyed the diverse, ensemble cast's voice acting, particularly that of Tom Scharpling's Greg,[178] Zach Callison's "exuberant and expressive"[179] work as Steven and Grace Rolek "singing her heart out" as Connie.

[183] Steven Universe, according to Eric Thurm, is a low-key, slice of life portrayal of childhood, an examination of unconventional family dynamics, a homage to anime, video games and other pop-culture mainstays, and a "straightforward kids' show about superheroes".

[185] Steven Universe also refers to Japanese cultural icons, including Neon Genesis Evangelion, Akira, Cowboy Bebop, Dragon Ball Z, Studio Ghibli movies and Junji Ito's horror manga The Enigma of Amigara Fault.

[185] According to Whitbrook, the series' "masterful sense of pace" allows it to integrate foreshadowing and worldbuilding into scenes, which makes an overarching, dramatic narrative emerge from what might otherwise be "monster of the week" episodes.

[174] Steven Universe's measured pace allows its characters to become "more complex and interesting than most of their counterparts on prestige dramas",[186] developing "as real people and not entities serving narrative functions".

[180] Its action scenes—such as Estelle's song presenting the climactic fight in "Jail Break" as a contest between Garnet's loving relationship and Jasper's lone-wolf attitude—are occasionally cast as philosophical arguments.

[177] Steven slowly grows from being an obnoxious, tag-along child to an accepted member of the Crystal Gems in his own right by the end of the first season, a change brought about by increased insight and experience rather than age.

[188] According to Kat Smalley of PopMatters, the Gems' alien nature, which prevents them from fully understanding the world they protect, is handled with "remarkable depth and intellectual rigor", even as they deal with human issues such as "depression, post-traumatic stress, and self-loathing" remaining from the long-past war for Earth.

[189] Smalley characterized Steven Universe as part of a growing trend of cartoons that appeal to adults and children alike, which includes Avatar: The Last Airbender (2005), its sequel The Legend of Korra (2012), Adventure Time (2010) and Regular Show (2010).

This is reflected in the series' outreach to minorities that seldom appear elsewhere in animation and its broader themes: instead of delivering genre-typical, mustache-twirling villains, Steven Universe "deals with issues of extraordinary violence and horror, depicts its characters in shades of grey, and subtly plays with matters of philosophy, morality, and interpersonal conflicts, all while refusing to reset any development to a status quo".

[175] As a self-aware pastiche of magical girl anime, the series subverts the genre's premises by having Steven embody the loving femininity of the typical magical-girl protagonist without ridicule or losing his masculine side.

Whitbrook characterized the series as being "about love—all kinds of love", including non-traditional forms such as the motherly and friendly bond between Steven and the Gems, and Garnet as the "physical embodiment of a lesbian relationship".

This, according to Rude, reflects the growing prominence of these themes in children's cartoons; previous depictions were subtextual or minimal, such as the 2011 Adventure Time episode "What Was Missing", the 2014 series Clarence or (more explicit but unexplored) the 2014 finale of Nickelodeon's The Legend of Korra.

[209] A full-length fan-made episode titled "The Smothering",[212] set in an alternate version of the story's continuity, was called "one of the more impressive pieces of work to come out of the Steven Universe fandom" in 2017 by io9.

[221] Krentz further argued this sort of participation by fans gives executives and creators feedback on who is watching the show and will buy merchandise, and on a related note, what counts as "good" representation.