The thriller - produced by Shah Rukh Khan and Karan Johar - released last Friday, saw the actor donning the rough look of a jungle-man. The film also starred Vivek Oberoi and John Abraham.
"It was fun! Shooting with Vivek (Oberoi) and John (Abraham) was a picnic. Vivek and I had worked together in "Yuva". But with John, it was a new experience, and certainly a pleasant one," he smiled.
Recent career setbacks, like "Blackmail" and "Zameer", don't seem to have deterred him. "It was only a phase. It has passed. It isn't really a setback since they were old commitments. Some of the films were done for the sake of friendship. Even during the shooting I used to say, 'This isn't going to work'. I was prepared. I'm relieved they're done."
However, "the sad part is when a good film like 'Yuva' don't do well. But what can you do? You pick up the threads and move on. It's all a part of the game. But given a choice, I'll still certainly do a film like Rituparno Ghosh's 'Raincoat' again, regardless of its box office performance," he insists.
Ajay admits his 2002-03 phase - during which he did films like "The Legend Of Bhagat Singh" and "Gangaajal" - was exceptionally fruitful. The chapter is revisited, he feels, with both "Kaal" and "Main Aisa Hi Hoon" depicting him in varied roles.
"Both are very special releases. I've never done such roles before and they're bound to get me noticed. Besides, these two films have turned out exactly the way they were meant to.
In "Main Aisa Hi Hoon", to be released Friday, Ajay plays a mentally-challenged man, fighting for the custody of his son. "The idea is picked from 'I Am Sam', but if you see the two films you'll see how different they are.
"In about 90 minutes of playing time, 'I Am Sam' allowed Sean Penn just 4-5 expressions. Here, we've songs, comedy - Indian cinema requires so much more. Even the language makes a lot of difference," he explains.
He admits, though, that he did watch Sean Penn's award-winning performance. "I analysed his performance but I've not copied him.
"I really didn't want to see him. But I did. It was impossible to follow him because the screenplay in 'Main Aisa Hi Hoon' is so much more layered. Sean Penn is brilliant. But in Hindi, the dialogues sound much more childlike. I've tried not to be excessively childish. But I couldn't help it."
Ajay loves the challenge of doing varied roles. "I don't mind being a different kind of a hero. I've always attempted unconventional heroism. I think audiences are ready for a change."
That kind of explains the assortment in his kitty at present.
There's Prakash Jha's "Apharan", Raj Santoshi's "Samna", John Matthew's film with Shahid Kapoor which is half-complete and a new Raj Santoshi project.
"I'm just finishing Prakash Jha's 'Apharan' and it has turned out to be even more hard hitting than his 'Gangaajal'. I'm very, very happy. Prakashji is in his element.
"Raj Santoshi's 'Samna' with Aishwarya and Akshay is a very gripping script. Raj Santoshi and I are working on another project which will hopefully be as interesting as 'Lajja', 'Bhagat Singh' and 'Khakee'," he reiterates.
Any film with wife Kajol? He shakes his head. "Nothing. But we're planning to revive our home productions soon. There're so many things I want to do, like become more media savvy. I am too lazy. But I'm making an effort."