John Cusack, who stars in the current film "Martian Child," already is getting rave reviews for next month's "Grace is Gone."

NEW YORK — With a filmography littered with teenagers, bachelors and guys trying to get the girl, John Cusack the dad is a new entry. In two new films this fall, Cusack plays parts where fatherhood is central.

"It signifies I'm getting older," Cusack, himself still childless, said with a laugh during a recent interview.

The 41-year-old actor, though, appeared remarkably the same as he did in 1990s "The Grifters."

"I don't feel any different," he said, smiling. "Recover a little slower, but that's about it."

Cusack first stars in "Martian Child," which opened Friday, as a science fiction writer who adopts a shy, eccentric boy. Next month comes "Grace is Gone," a Sundance Film Festival hit in which the actor portrays a former soldier who delays telling his daughters that their soldier-mother has died in Iraq by taking them on a road trip.

In "Martian Child," he essentially keeps his usual screen persona: witty, aloof, idiosyncratic. It's easy to envision his character as the grown-up version of Lloyd Dobler in 1989's "Say Anything" or the slightly older incarnation of Rob Gordon from 2000s "High Fidelity."

In "Grace is Gone," though, he gives a quiet and grief-filled performance for which he's getting considerable buzz, courtesy of a Harvey Weinstein-orchestrated Oscar campaign.

The duality of the roles is typical of Cusack, who tends to alternate between studio pictures (1997's "Con Air," 2001's "America's Sweethearts," 2005's "Must Love Dogs") and more offbeat indie fare (1999's "Being John Malkovich," 2002's "Max").

"I keep trying to explore stuff that I like and balance the business with personal passions," Cusack explained.

Clearly differentiating between the motivations behind "Martian Child" and "Grace," he said: "One the studio wanted me to do, and the other was a script I really loved."

Not one to ever totally go Hollywood, Cusack has referred to fame as a "24-hour petting zoo" and lamented how studios view him as a "brand."

"It's only when you try to get jobs or get certain things made from the studio that you realize what that is," said Cusack, who speaks barely above a whisper. "You just understand it when people tell you 'No.' It's mostly just more what they think will make money. That's really it. 'Can we get Johnny Depp?'

"I'm interested in doing stuff that people I admire do, which is try to explore being human and admit that you're human," he said. "At least admit it in film, if you can't do it everyday in life."

For some, living up to the glib charm of Cusack's earlier roles is difficult. Writer Chuck Klosterman once labeled Cusack the "neo-Elvis," claiming a generation of women will forever be in love with him.

But while "Martian Child" recalls that side of Cusack, "Grace is Gone" reveals a new dimension to the actor. Writer-director Jim Strouse (who wrote 2005's "Lonesome Jim") wrote the part with Cusack specifically in mind.

"I just thought it required some things I knew that he could do but hadn't been asked to do," said Strouse. "He's got so much energy in life and on screen and he kind of can't contain himself. I just thought it would be interesting to see him say very little — kind of the opposite of everything he's known for and so good at.

Others have been enthused as well, including Weinstein, co-chairman of the Weinstein Co., who has shepherded numerous small films to Oscar success.

"I truly believe he has a breakout performance in 'Grace is Gone' and I hope that he will be recognized this awards season," Weinstein said in an e-mail.

Asked about his thoughts about a possible Oscar nomination (which he's never received), Cusack replied: "It's good for the movie and would be great for me. It's kind of like the prom, right? You wouldn't want to admit that you want to go, but you probably secretly want to be asked."

Film critic David Thomson in his "Biographical Dictionary of Film" wondered of the ever-youthful Cusack: "So when is he going to be emphatically grown-up?"

With "Grace is Gone" and "Martian Child," Cusack may have answered that question.