What's happening with The Last Guardian, the eye-catching PlayStation 3 exclusive once due out late 2011?

We asked Sony Worldwide Studios chief Shuhei Yoshida that same question during an interview at Gamescom today.

"The team is still working on it very hard," he replied. "There are certain technical issues they've been working on. That's the period of time when the game, looking from the outside, doesn't seem to be making much progress. But internally there is a lot of work going into creating the title."

The Last Guardian failed to show up during Sony's Gamescom press conference yesterday. That absence, following similar no-shows at Tokyo Game Show 2011 and E3 in June and the news that superstar developer Fumito Ueda is working on the game as a contractor, has only served to increase the concern around the game's status.

So what's taking so long? According to Yoshida, Sony Japan Studio has had to completely re-do work that had got the game to a playable state.

"We had the game playable," Yoshida explained. "At one point we felt that it would be produced for a certain time period. That was the time we prematurely talked about the launch window. But it turned out the technical issues are much harder to solve. So the engineering team had to go back and re-do some of the work they had done."

Some have suggested the game has been switched from PlayStation 3 to PlayStation 4, which is reportedly due out late next year.

But Yoshida insisted The Last Guardian remains a PS3 title. "The game is developed on PS3," he said.