Adaptation Dye-Job: Although a minor character that wound up not amounting to anything beyond a cameo, Aquagirl (as opposed to the earlier "Gill Girl" in the run) was greatly revamped when she made her debut. Her hair went from being brown to a deep green, and her blue eyes became gold... along with suddenly becoming blue-skinned, having webbed hands and feet, and some gill markings on her face.
Adaptation Expansion: Backstories, expanded filler, and even post-Season 5 ideas are given deeper detail all throughout the comic's run.
The Cameo: One of the issues include a cameo by Batman himself, watching the Titans from afar and proud on what Robin has become.
Canon Foreigner: It features some newly-created villains exclusive to this continuity (and who never got to be in the show), such as the Kwiz Kid (a teenage Expy of the Riddler), Kid Kold and Ice Kate (younger counterparts to the Flash Rogues King Cold and Golden Glider), and the trio of Rock, Paper, and Scissors. There's also Aqualad's friend Gill Girl, who appears to be a cross between Aquagirl and Lagoon Boy.
Expy: Ice Kate and Kid Cool are teenage versions of Golden Glider and Captain Cold.
The Kwiz Kid is basically a younger Riddler, and Gill Girl is a mashup of Aquagirl and Lagoon Boy (an actual version of Aquagirl would later be briefly seen towards the end of the series as an image on a screen, as well as in a chibi gag).
The version of Aquagirl seen in issue 50 and the chibis seems to be a less extreme example, falling somewhere between looking like a fish person (with gills, webbed feet and blue skin) and being more humanoid (with her face and hair).
Freudian Excuse: Red Raven, in her self-titled issue 44 (a continuation of 42), attacks and destroys anything having to do with fathers (Founding Fathers display at the museum, Fathers Day gifts at stores, etc.).
Give Her a Normal Life: When Geo-Force finds out whats happened to Terra, he doesn't bother revealing himself to her, noticing it's the first time he's seen her happy. Terra, spotting and recognizing him, watches as he leaves.
Humongous Mecha: Issue 9 introduces the Titans Go-Bot 5, which the team uses to fight Gizmo's giant robot. It's later used to fight a Professor Chang-controlled Beast Boy, a.k.a Garsaurus Rex.
Last Episode New Character: Cassie aka Wonder Girl 2 who shows up in the next to last issue of the series. She does get a cameo in the final issue however.
Flamebird and Mirage also show up as new Titans in cameos in the final issue, although an alternate future version of Mirage appeared in an earlier story (issue 48) and Flamebird had a brief cameo in issue 50, on a screen showing potential new Titans (along with GO! versions of Azraelnote The alien "space angel" hero who appeared in an arc of the original New Teen Titans comic, not to be mistaken with the '90s anti-hero of the same name, Aquagirl, and Golden Eagle, who otherwise never got roles in the series). Two Titans named "Soldier Boy" and "Soldier Girl" also cameo in the final story.
Legacy Character: An interesting variation: issue 54, "Makes You Wonder", features Cassie Sandsmark attemping to usurp Donna Troy's position as Wonder Girl.
Leaning on the Fourth Wall: In "Magic and Misdirection", Mumbo opens a trap door that makes Beast Boy fall out of the panel. Starfire and Terra follow, and we're treated to a few pages of them wandering around the borders of the page while Super-Deformed.
Raven gets a lampshade hung on her more goth-like appearance.
There's also the Terror Titans of Issue 48, three of whom are Red Robin, Arsenal and Tempest — the same names used by certain older versions of Robin, Speedy and Aqualad. As their team name indicates, they're decidedly twisted versions.
That same issue features Raven opening doors to various alternate realities, including the original-flavor Teen Titans from the Silver Age and, in a blink-and-you'll-miss-it peak, Secret and Lobo of Young Justice.
In issue 39, a Valentine's Day issue, Speedy and Chesire get hit by an arrow and fall in love. In the comics, they briefly fell in love and had a child together.
Nice Job Fixing It, Villain: According to the Wildfire issue, Blackfire has sold off Starfire to the Gordanians to keep them from invading Tamaran. Watching the episode "Go!" from the main cartoon shows how well this turned out.
Although she may not have been aware she was naked.
Race Lift: Although a minor example (as the series was cancelled before he or others could be developed), the cameo of Golden Eagle falls under this. In the original DC Comics, he's a blond Californian teenager. In Go, he's revamped to be an Egyptian boy, probably to tie him better into the original Hawkman mythology.
Super-Deformed: Other than the margin-gags, there's also issue 18, "When Chibis Attack". Raven even explicitly refers to their tiny counterparts as "chibi".
Take That, Audience!: In "Stupid Cupid", Raven remarks on how all the "shipping" is stupid, after Larry attempts to pair up all the Titans with each other. Depending on the fan, it was either taken as a cathartic jab at shippers or condescending and insulting to fans.