Gotham has come a long way since its start: it has become quite popular and it is appreciated by a huge percentage of comic readers.
The show has taken its distance from the comic books, becoming its own independent alternative universe.
The first season explored how Bruce Wayne changed when his family was killed and the birth of Gotham's most notorious villains, developing their criminal abilities and schemes in the next seasons.
Season 4 has come to its mid-season finale; this part of the show introduced new villains, like Sophia Falcone (notorious Carmine Falcone's daughter) and Professor Pyg, a quite unstable serial killer.
But before talking about the villains, perhaps the hero's development is of more importance. Bruce Wayne seemed to be on a good, although dangerous path -- the vigilante's. In the first episodes his investigations revolve around Ra's Al Ghul, who has chosen Bruce as his 'heir'. But to be sure Bruce is the right choice, Ra's Al Ghul aims to convince Bruce to kill him by telling him that would save other people's lives. Bruce does actually kill Ra's to everyone's surprise, taking a huge step away from the material source in which Bruce Wayne/Batman's first moral rule is to never kill. It was a dangerous step to take for the show, considering that he did something that normally Bruce Wayne opposes to (the show actually respected this one moral rule in the previous seasons, when Bruce was about to kill his parents' murderer). But in this way the show also re-confirmed its intention to be its own alternative universe with its own stories.
Bruce, however, didn't have any actual good character development after his first murder, indeed all he did after that was to get drunk and party, developing an attitude that concerns Alfred and that will cause Bruce to look for another legal tutor.
And while Bruce's persona isn't really changing, Gotham City's criminals are evolving and plotting to achieve their nefarious goals.
We got to see Jonathan Crane becoming Scarecrow, though he still didn't have a big role --a good opportunity that they wasted since Scarecrow has the potential to spread fear all over Gotham and to make the show much more interesting.
Penguin has, in this first part of the season, created the Pax Penguina -a clever, sinister idea- which allows criminals to commit crimes, if they possess one of Penguin's cards, without having to face any consequences after. He also, astutely, corrupted law enforcement in order to make the GCPD release criminals if they have the pax penguina card.
Obviously Jim Gordon, Gotham's hero, does not approve and is determined to end the Pax Penguina and Penguin's empire in general. That's why he asks for Falcone's help and that's when Sophia Falcone is introduced. Sophia's plan consists of getting the Falcone name to rule Gotham once again, and in order to do that, she pretends to be Oswald's friend. This allows her to steal everything he built, and she helps Jim get rid of dirty cops by hiring Professor Pyg.
The latter was quite a creepy villain, his twisted schemes and morals made him interesting, but he would've been far more dangerous if he acted on his free will instead of being hired by Sophia.
Actually, at the start, Sophia Falcone doesn't really seem to be a big deal; Oswald's development is proportionate to his thriving empire's, which means that even the law isn't able to bring it down (just yet).
But by every episode Sophia seems to grow more determinate and capable of actually taking over the city, not by simply using a lot violence, but mostly through twisted games and mental tricks. She turns out to be fearless and merciless when it comes to getting what she wants --she makes that pretty obvious when she architects her father's death.
In the mean time Barbara Kean is actually alive --more precisely resurrected by Ra's Al Ghul-- and she proposes Tabitha and Selina a deal to gain more money and therefore power. In this way the Sirens get back together, although their role isn't really a big one in this first eleven episodes.
After season 3's ending, Selina Kyle's last scene made everyone think we'd see much more of Catwoman. But truth to be told, besides a few little attempted robberies, she doesn't do much and she doesn't have a significant role, compared to the previous seasons.
The Riddler/Edward Nygma seems to have lost his mental abilities after being frozen (by Penguin) for months. He looks for help and finds it in Lee Thompkins, who came back to Gotham to help poor people --she considers it a debt she has with Gotham's citizens due to her previous actions (with the Tetch's virus).
After helping each other out and facing problems together they actually find themselves getting along again and, at the end of the season, Edward realizes he's in love with Lee. That's the last taste we got to see of the two of them; fans are not sure where writers are going with both of them, but since in the trailer Riddler seems to be back, Lee is probably going to leave him at his criminal career. It did slightly look random to make Ed fall in love with her, but they did used to be friends before he became a villain; they might turn out to have an interesting dynamic, even as just friends.
In the new trailer some of the most loved Batman's villains, like Poison Ivy and Jerome (Joker), are finally shown.
Ivy was at first working for Penguin as she believed they were friends, but since he didn't really treat her well --just like anybody else-- she left and decided to go on her own.
So she went looking for some 'miraculous' compounds and once they're found, she drinks them. After this event Ivy disappears, probably because her body is going through the process of becoming the plant-human hybrid she is in comics, which requires time. Before getting tired of the way she was treated her personality was quite childish (not really the Femme Fatale we all know) and she didn't really have any potential to become a more significant villain like Sophia or Penguin, but in the trailers she seems to finally be at the end of becoming a villain.
About Jerome, he appeared in Arkham Asylum in the cell next to Penguin's. Via social, fans were told we'd finally get to see Joker, so Jerome is expected to be 'reborn' with the white skin and red lips and to completely become the clown prince of crime.
The trailer promises good things, such as the best villains to mess the city up and, although season 3 didn't start astonishingly, I believe that the show still has potential to be one of the most entertaining comic-book-based shows.