The first Teenage Mutant Ninja Turtles movie to be done in complete CGI.After training for years in Central America at the request of Splinter, Leo returns home to New York and reunites with his brothers.Meanwhile, super wealthy mogul Max Winters has gained possession of four stone statues, one of which was retrieved by his client April. We learn that Winters is a warlord made immortal thousands of years ago upon contact with a rift in dimensions, and that those statues are his generals, who were transformed into living stone. Winters also has hired guns in a reformed Foot Clan led by the mysterious Karai. As all of this is happening, monsters are starting to appear all over the city.The turtles must overcome their personal differences and become a whole once again to get to the bottom of things and quite possibly save the world.
Anachronism Stew: The four ancient Aztec generals from 1000 BC had SPANISH names. The Spanish language did not even exist back then. And the Spanish language did not arrive to Mexico until after 1492 AD. Also possible example of Spexico.
Battle in the Rain: Leo and Raph's climatic battle, after all the tension between them in the movie and the revelation that Raph is the Nightwatcher, takes place on a dirty rooftop at night, in the rain, echoing the sadness of the scene; that in the end, all the issues between the two brothers has led to this.
Berserk Button: Also Raphael in the fourth movie when Leonardo taunts him on the rooftop
Leonardo:"...And more importantly, I'm BETTER than you!"
Raphael: "I'm gonna have to disagree with you on that one."
Raph proceeds to kick Leo's shell.
Big "NO!": Raph gets one when he returns too late to stop the Stone Generals from taking Leo.
Bond Breaker: Leo's extended training trip drove the brothers apart. Even when he returns, time has taken its toll on all of them and they aren't able to function as a team anymore, the biggest conflict being between Raph and Leo. The tension between them finally blows out into a no-holds-barred fight after it's revealed to Leo that Raph is the Nightwatcher. A fight which, to be quite honest, was a long time coming between the two. The brothers finally reconcile during the final battle, after saving Leo.
Broad Strokes: The events of the first three movies, as applied here. It was basically confirmed by Word Of God that, they did happen, just not in exactly the same way.
Call Back: Casey shouts "Two minutes for high sticking!" after hitting a Foot ninja in the face, which was one of the "penalties" he used on some thugs in the first film.
Chekhov's Gun: At one point, Casey accidentally breaks a vase in Max Winters' home, causing an alarm to go off and several metal security doors to close and keep people from leaving. Later, seeing the Foot Clan coming to fight the turtles in Max's home again when they are hopelessly outnumbered, Casey breaks another vase deliberately, causing the doors to shut once more and keep the Foot Clan out temporarily.
Splinter's trophy room contains a whole collection of references to the previous films. Shredder's helmet and staff, a Foot Ninja mask (based on those worn in the previous films, as opposed to the more modern members led by Karai) the T.G.R.I. canister, the Time Scepter, Walker's hat, Lord Norinaga's helmet and the armour of the Honour Guards whom the Turtles took the places of in the third film.
It also contains some things from other continuities, such as the helmet of an exterminator-themed mutant from the comics and a destroyed Mouser robot.
One of Donatello's first scenes is of him handling tech support calls over the phone. But one call: "No, sir, invoked I'm not playing hard to get. I'm telling you, it's not that kind of phone line!"
Casey and April "shacking up" may qualify. It's rare to see unmarried couples living together in family films, at least in that sort of relationship. Somewhat mitigated by conversation suggesting that April wants to get married but Casey isn't ready.
Black Betty plays in the background during Raphael's fight with the Jersey Devil in the diner, complete with the line "She Really Gets Me High" intact. (Listen for yourself (around the 1:54 mark): http://www.youtube.com/watch?v=Ij7SBz8xYuY)
The Gloves Come Off: After Leo learns that Raph is the Nightwatcher, the two brothers get into a gigantic argument that eventually devolves into a duel. Raph, having already lost the vision-restricting helmet, draws his sais, the weapons he's been trained with since birth, and Leo, realizing that Raph is serious, draws his swords, indicating the two brothers are ready to fight for real.
Kick the Dog: The Vampire Bat, one of the 13 monsters, eats a pigeon offscreen, then smiles menacingly.
Let's Get Dangerous: Raph. After fighting Leo in his Nightwatcher gear and being outclassed, he pulls out his sai, the weapon he's trained with from birth, loses the helmet which constrained his vision, and puts up a better fight, before nearly killing Leo after it's revealed (to Leo) that his brother is the Nightwatcher.
Monster of the Aesop: Raph is having issues with Leo's leadership. General Aguila and Yaotl are also brothers with similar issues. While Leo and Raph reconcile at the end, Aguila ends betraying Yaotl.
Mood Whiplash: The funny scene with the Raphael and a tiny monster is followed by a scene where Raphael and Leonardo have a falling out and fight, all culminating in Leonardo getting captured by the villains.
And in the final battle, we cut from an epic battle to Casey and April arguing about reckless driving, Karai snarking that they seem like they should be more concerned with the giant monster chasing them, the Foot Ninja nods in agreement, back to epic battle.
My God, What Have I Done?: Raph's reaction after defeating Leo in their rooftop battle. He let his emotions get the best of him, and nearly killed his brother. Leo's capture soon after and his inability to stop it only intensified those feelings.
Poor Communication Kills: Though not outright stated in the film, it becomes clear that this one of the main issues in the conflict between Leo and Raph. Leo's departure and time away from home was obviously hardest on Raph, but they aren't able to fully communicate with each other about it, which led to the gigantic blowout between them when Raph was revealed to be the Nightwatcher and the fight that subsequently followed, all culminating in Leo's capture by the villains prior to the climax of the film.
Still Got It: Master Splinter says this when he kicks a couple of monsters back into the portal. Though, to be quite honest, he never lost it.
The Climax: While technically, the climax is when the turtles battle the stone generals and attempt to close the portal threatening to release an army of monsters onto the world, it really feels more of Dénouement. The real climax is is Leo and Raph's fight, as the conflict between them is more at the forefront than the plot of the villains. Ultimately, after the blowout between them and Leo's subsequent capture, the two brothers finally find it in themselves to reconcile during the Final Battle.
Took a Level in Badass: April is now a full-fledged Action Girl capable of taking on Foot Ninjas alongside the others, and matching Karai in an equal one-on-one fight, having been trained by Splinter during the time skip.