These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
The film's title is simply John Carter, he doesn't really get the title of "John Carter of Mars" until the end of the film. (However fortuitous, the lack of Mars in the title was originally due to Executive Meddling.)
The film actually lampshades this by displaying the title on screen a second time at the end of the film... this time in full.
The first trailer featured the Arcade Fire song "My Body is a Cage" as covered by Peter Gabriel. The lyrics start with: My body is a cage / That keeps me from dancing / With the one I love / But my mind holds the key. At the end of the film John's Earth body keeps him from being with Dejah, and he uses his wits to find a way to return to Mars. (His Mars body is a duplicate while the original is left in suspended animation.)
The second trailer had a symphonic instrumental cover of Led Zeppelin's "Kashmir". though unused, the lyrics start with: Oh let the sun beat down upon my face / Stars to fill my dream / I am a traveler of both time and space / to be where I have been.
Germans Love David Hasselhoff: It had the biggest opening day ever and the fourth biggest opening weekend ever in Russia while the American opening was mild. The Russian first-week gross amounted to $16.6 mln, or 56% of the U.S. gross; given the huge difference in cinema attendance figures and infrastructure between the two countries, it really is a spectacular achievement.
Nightmare Fuel: The cries of the just-hatched baby Tharks are... unsettling, to say the least...
Older Than They Think: The source material of this film inspired hits such as Star Wars and Avatar. Or inspired the works which inspired them. Yes, the "John Carter"-novels have been around for that long.
In fact, Superman was basically a Captain Ersatz of John Carter himself, when he first debuted (just coming from an alien planet to Earth instead of the other way around).
One-Scene Wonder: Kantos Kan (played by James Purefoy) doesn't have much to do besides act as Number Two to his king, but he gets the spotlight when he helps John escape one of the several times he's taken prisoner or detained.
Pungeon Master: As usual, Michael Giacchino's titles for the tracks from the score are about twenty percent terrible puns: 'A Thern Warning', 'Thernabout', 'The Carter They Fall', and so on.