In 2018, some superheroes went up, some went up, up, and some just went away.

Superhero stories are as mainstream as apple pie and baseball. Just ask Marvel, which has minted billions of dollars for Disney, and every five-year-old in a Batman t-shirt.

Even as superhero films continue to flood your local multiplex like a comic-book shop writ large, the story on television is a less successful one that leaves fans and experts with little cartoon question marks coming out of their heads. In a year when there were more superhero series than ever, there were also more super-fails.

An incomplete list of the superhero TV shows that aired new episodes in 2018 includes “Black Lightning,” “Krypton,” “Cloak & Dagger,” “Supergirl,” “The Flash,” “Luke Cage,” “Iron Fist,” “DC’s Legends of Tomorrow,” “Arrow,” “Titans,” “The Gifted,” “Legion,” “Daredevil,” “Gotham,” and a four-way crossover between CW series called “Elseworlds.” Hulu’s Marvel series “Runaways” got in under the wire with a second season on Dec. 21.

But the genre is also starting to contract. The iron fist (pun intended) of cancellation has pummeled even the strongest series. And many that remain are no longer essential viewing, even for the most devoted fans. Simply put, 2018 in superhero TV wasn’t all that super.

For years, CW has aired a delightfully solid if not superb slate of DC Comics-inspired shows. The network was riding high in late 2017 on the heels of a great annual crossover event between "Supergirl," "Arrow," "Flash" and "Legends," and started 2018 with the lauded “Black Lightning.” But over the course of the year, “Supergirl” and “Lightning” fell victim to the same problems “Arrow” and “Flash” had: Too many heroes and too much complication. The 2018 crossover was just OK. “Riverdale,” based on the Archie comics, has surpassed all five series as CW’s buzziest. “Legends” remains the sole comic-book bright spot for the network, the only show to embrace chaos instead of collapsing under it, even though it started off messy in 2016.

A misguided tone and bloat plagued many returning superhero shows. FX’s “Legion” started out as one of the weirdest and most experimental shows on TV, but its second season withered into a self-indulgent mess. “Runaways” has some of the greatest source material to work with, but a just-OK first season will be followed by a more frustrating second.

DC expanded its footprint with a new streaming service, DC Universe, that featured “Titans,” a violent and risque take on the Teen Titans heroes that some critics liked, but was essentially a blip in the media cycle.

The disappointing head-scratcher of the year was Netflix’s sudden cancellation of three Marvel series, “Iron Fist,” “Luke Cage” and “Daredevil.” “Iron Fist” was a dumb show done badly that will likely be forgotten, but “Cage” and “Daredevil” are already sorely missed. Both were celebrated among fans and critics, and and the recent third season of "Daredevil" was outstanding. There is no word on the survival status of the streaming service’s “Punisher” and “Jessica Jones,” but it seems counterintuitive to believe that they will survive the purge.

In the world of genre TV, unceremonious cancellations of cult TV shows are nothing new (just ask fans of “Firefly”), but the streaming era creates a false sense of security. These were business decisions, likely influenced by Netflix’s inexplicable measurements of success, the bureaucratic divides between Marvel Studios and Marvel TV and the forthcoming Disney streaming service. But they also felt like Netflix and Marvel were closing the door on a distinctly mature and thought-provoking take on the genre.

Even with disappointment and bad storytelling so widespread, there were some heroes worth rooting for. Watching Freeform’s “Cloak & Dagger” is a reminder of what makes superhero stories great and how television can be a great medium to tell them. The series combines electric young stars, a slow but steady pace and unique superpowers to create something special. It’s the best superhero series on the air.

And there's plenty to look forward to in 2019. Netflix will go further down the well of comic-book source material in February with “The Umbrella Academy,” a dark and violent story about a misfit family of superkids who are now dysfunctional adults. The Disney streaming service, due late next year, has several Marvel projects in the pipeline, with bigger-name heroes than have surfaced on TV before. And there's still the possibility that any number of series that faltered this year could dust themselves off and start flying again.

After all, believing the impossible is possible is part of loving superheroes.

For more on the best and worst of pop culture in 2018, listen to USA TODAY's geek culture podcast, "The Mothership."