The biggest story for Gotham's brief winter arc was the return of Jerome and how his resurrection would change the city forever. Now that the arc is over, however, it seems like there wasn't much of a difference between this and the last few times he attacked the city, besides a little escalation. The biggest twist was definitely Jerome kidnapping Bruce Wayne, though something very similar already happened in Season 2, when Jerome was first killed by Theo Galavan.
To be completely honest, even with all of that happening, seeing how landlines somehow still work despite a massive power outage and explosion was pretty distracting. (This is something that's actually true, but nonetheless, it feels a little convenient that everyone in Gotham City has a corded phone.) Part of what keeps the story somewhat grounded is Jerome's pretty vague motivations. His justification for his night of terror sounds a lot like The Purge, strangely enough, but with a circus twist. And while I'm not sure why this theme park has electricity when nowhere else in the city does, it does feel like the kind of ghoulish prank that the Joker would pull, even though Jerome still hasn't been identified as such.
At one point, Jerome outright tells Bruce, "Gotham has no heroes" as some heroic music swells, a reminder that this teenager will eventually become a vigilante who beats up petty criminals in his time off from being a billionaire. Right now, though, he's just a very angry teenager — one who actually comes close to murdering Jerome when the tables finally turn.
Ultimately, Bruce cements his "no killing" rule, the one that will characterize his time as Batman and that he first came to when he decided not to exact his revenge on the man who killed his parents. But that's where Gotham's winter finale leaves off, with Bruce one step closer to his future, and Jerome's face lying on the sidewalk.