"Marvel's Agents of S.H.I.E.L.D." is still in the midst of its first season, but the ABC series has inspired what feels like several years' worth of feedback and criticism from fans and critics.

Launched last September with heavy expectations, the show --a small-screen spinoff of Marvel Studios' highly successful films -- has maintained strong ratings, yet many have expressed disappointment over it not being quite what they hoped it would be. Common requests include a desire to see a stronger connection to the larger Marvel Cinematic Universe, more significant comic book characters introduced to the series and a turn away from standalone episodes, perceived by some as delaying big picture reveals like the true nature of Agent Coulson (Clark Gregg)'s return from his "Avengers" death.

During a recent visit to the show's Los Angeles-area set attended by CBR, it appeared the series is set to address these complaints directly, starting with the news that recurring character Mike Peterson (J. August Richards) will be revealed as Deathlok in upcoming episode "T.R.A.C.K.S.," airing on Feb. 4. While obviously not an Iron Man-level character, Deathlok has a lot of comic book history behind him, as both a starring and supporting character, and is of a higher stature than prior comic book characters who have debuted on "Agents of S.H.I.E.L.D." (Victoria Hand, Donnie "Blizzard" Gill, Franklin "Graviton" Hall).

"Agents of S.H.I.E.L.D." Ups Comics Cred by Adding Deathlok, Lorelei

"Deathlok had been on our radar from the beginning," co-showrunner and executive producer Maurissa Tancharoen told CBR. "He was at the top of our list of Marvel characters that we could bring in. It seems like a nice progression for Mike Peterson -- when he becomes Deathlok, you're always going to root for the Mike Peterson that's still in there somewhere."

From the very first promotional footage released from the series last year, observers speculated that Richards was playing a superhero from the Marvel mythos, with Luke Cage and Rage the most common guesses. Turns out those fans were actually on the right track.

"If you look at the pilot, there's a moment where he's standing in the window and he turns around and says, 'This is an origin story,'" Jeph Loeb, veteran comic book writer, head of Marvel TV and "Agents of S.H.I.E.L.D." executive producer, said to reporters. "You just didn't know what story."

Loeb also announced last week that Lorelei, a character created by Walt Simonson during his legendary run on "The Mighty Thor," is headed to "Agents of S.H.I.E.L.D." Played by Elena Satine, Lorelei debuts in the episode featuring Jaimie Alexander, who is bringing her "Thor" role of Lady Sif to TV for the first time.

"There are still people online going, 'We don't understand why Iron Man isn't on the show.' Well, you know what? He's not," Loeb said. " I love Robert -- [but he's] not coming by any time soon. But if we are going to have Lady Sif, if we're going to have Lorelei, if we're going to have Deathlok, if we're going to have Stan Lee [appearing in "T.R.A.C.K.S."], that's that stuff that we hope that same fanbase is going, 'That's what I was talking about. I wasn't really thinking that the Hulk would be on the show, but if you give me Lorelei, I'll come back next week.'"

As for those "one-off" episodes, the prevailing message from the set visit was that viewers shouldn't think of them as throwaways, for reasons promised to become clear.

"These standalone episodes actually have a payoff, planting a seed in our universe that will then pay off," said co-showrunner Jed Whedon. "You start to see that [Ian] Quinn's involved with the Clairvoyant and Centipede; all these things are pieces of a whole that we try to build in a way that was respectful to the films, but can pay off. Now, we're excited to get to the point in the season where it does pay off."

Of course, getting to those payoffs requires a degree of patience, something not always guaranteed from an audience.

Sif Moves From "Thor" to "Agents of S.H.I.E.L.D."

"Did you ever do that thing where you ate the healthy stuff first, and saved the dessert? We're deep into dessert, right now," Gregg told a group of reporters. "That work of setting up this world and these characters has been done. If you don't do that well, and take the time to do it, no one cares that much about what happens after that."

Executive producer Jeffrey Bell theorized that recent changes in the medium of television itself have altered viewer expectations.

"I think storytelling is changing on television," Bell said. "I think cable is doing it, and Netflix is doing it, and the velocity of story is going faster. On 'X-Files,' it took seven years for Mulder to discover, 'Oh, that's what happened to my sister.' You could tell a mythology episode, and then put it down and tell five monster episodes, and people were like, 'OK.' And now it's not."

"[I] don't think we could have gone 10 seasons with Clark not putting on the cape and the S in present society," Loeb said, referring to his time as a producer and writer on "Smallville." "At the end of episode 4, people would have said, 'We don't get it -- where's the costume? Let's go.'"

Another issue the "Agents of S.H.I.E.L.D." team has navigated is presenting a show where the "Marvel" brand name is right in the title while the main cast consists of nearly all brand-new characters. Audiences first met Phil Coulson in 2008's original "Iron Man" film, but the other five main characters all debuted in the pilot.

"We had an extraordinary challenge, and something that I'm not sure enough people give us enough credit for," Loeb said. "Marvel movies have the benefit of, 'It's Iron Man. It's Hulk. It's Thor. It's Captain America.' We had the fantastic Clark Gregg as Agent Coulson, a character who existed from a few of the Marvel films, and S.H.I.E.L.D., which, at best, is an amorphous government organization that, unless Samuel L. Jackson was going to come in and explain it to you every week, you were going to have to come along on the ride.

"The gift that Joss [Whedon] and Jed and Maurissa and Jeff and our extraordinary writing staff came up with was, we introduced brand-new characters into the Marvel Universe," Loeb continued. "They didn't exist in the comic books; they didn't exist in the movies. When Agent Grant Ward stepped onto this shift, that was a brand-new opportunity for an audience to be able to go, 'We like that guy. We want to know more about that guy.'"

Series lead Clark Gregg also defended the ratings pattern of the series, which has received scrutiny for dropping off after its series premiere, when it drew a lofty 12.12 million viewers.

"We care about the live audience," Gregg said. "But the live plus seven numbers are ridiculous. If you pause the show to go pee, you move to the live plus three or live plus seven -- I personally don't know a lot of people who aren't watching television that way. If you look at how well our show is doing in those numbers, I'm quite encouraged."

With 10 episodes left in its freshman season, the cast and producers say the action will ramp up further, though nobody would provide many more specifics about what's left to come.

"It's S.H.I.E.L.D., and we're dealing with life and death superhero situations," Chloe Bennet, who plays Skye, told CBR. "I knew it was going to get pretty insane, and it's getting even more insane than I thought."

"Agents of S.H.I.E.L.D." was always going to be a unique challenge for Marvel and ABC, but Loeb seems pleased with how things have fared so far.

"When you ask -- 'What has been the hardest thing to learn?' -- it is how to make the show," Loeb said. "We have x dollars, y days and have to be on the air on z day. That is not going to change. We had to be able to learn how to do that, and judging from the reaction, it seems like we're doing it pretty well."

"Marvel's Agents of S.H.I.E.L.D." returns with a new episode 8 p.m. Tuesday, Feb. 4, on ABC.