"Gotham" has come to the end of its run. An easy way to describe the series is as the Batman version of "Smallville". That long-running series chronicled Clark Kent's journey to becoming Superman. Both were neither the first nor last adaptations of the characters.

Really, though, it's more complicated than that. "Gotham," a series not for the light-hearted, tended to be significantly darker than "Smallville." It also often focused more on how the supporting characters reached their destinies, rather than on Bruce Wayne. All of them have flaws and redeeming traits, many of which took on their iconic looks for the show's final act.

Beware of spoilers.

The finale jumps ten years into the future

The penultimate episode left audiences with mixed emotions. Some elements left on a feel-good note, while others had more of a melancholy tone. Happier events included heroes and villains joining forces to save Gotham. Jim Gordon finally becomes Commissioner Gordon, as USA Today reports. In addition, he, Lee, and Barbara have formed some sort of odd familial unit. Oswald Cobblepot (The Penguin) and Edward Nygma (The Riddler) put their bygones in the past.

On the sadder side, Bruce decides to leave Gotham. He tells his loyal butler Alfred that he will return when he can protect the people he loves. The Batman-to-be doesn't say this to Selina Kyle, his love interest and the future Catwoman.

Instead, he leaves a letter behind for her. She rushes to the airport, only to find the plane has just left.

Fast-forward to ten years later. Gotham is abuzz that Bruce is coming home for the opening of a new Wayne Enterprises' building. Jim is preparing for retirement. Barbara is a respected, legitimate businesswoman. Selina is a jewel thief.

It also seems that whatever good feelings Jim had for Oswald and Nygma are gone. Despite the bond of their working together, he has since arrested them and is responsible for their imprisonment. The finale features both of them regain their freedom. While Oswald's is planned, there is a twist to Nygma's escape. Both are rather upset with Jim and aren't afraid to show it.

And, as the audience learns, Bruce has become Batman.

For much of the episode, there are only brief glimpses of the caped crusader, until the very end when he is showcased in all his glory. And he and Selina seem set for a tongue-in-cheek relationship that Batman and Catwoman fans know well. She was still rather hurt by his abrupt disappearance, though she seemed somewhat placated by his promise of never leaving again.

The swan song of "Gotham" features of a number of nods that Batman fans should recognize. From the costumes to Jim's daughter's fighting spirit, there's a possible foreshadowing of her future as Batgirl.

Ultimately, the television run of "Gotham" last roughly half as that of "Smallville".

Both series put their own original spin on the origin stories, in addition to sticking to the source material. And more prequel series have been developed, likely increasing the drawing of parallels.

Some elements left to be debated by fans

As is to be expected, there are some things that can be the topic of debate among fans. One of them is the re-casting of Selina for the finale. Camren Bicondova had played the role throughout the run of the series. Apparently, it was thought she wouldn't credibly look ten years older in the finale. Instead, Lili Simmons took over the role. The reasoning is sound, but it seems wrong to not have included Bicondova in the finale: Not even in some sort of flashback.

There is also the matter of the man who might be The Joker. It should seem obvious, but nothing is ever explicitly said that's who the character is. And, as Deadline reports, executive producers won't confirm the character's identity. His make-up also became a polarizing topic.