Rockstar development chief Jeronimo Barrera believes Grand Theft Auto IV: The Lost and Damned packs a full game's worth of content and sets a new benchmark for downloads.
"We've done a full game in my opinion, in terms of the production quality and the new gameplay mechanics. We've literally reached the maximum memory size that we can do for DLC with Microsoft.
"You're going to get a lot of game," he added, offering only "hours and hours" as a gameplay estimate.
Grand Theft Auto IV: The Lost and Damned launches exclusively on Xbox 360 tomorrow for 1600 Microsoft Points (GBP 13.60 / EUR 19.20).
Players will become biker-gang boss Johnny Klebitz, whose story plays out separately to Niko Bellic's. The idea is that Liberty City houses all sorts of stories. And that, explained Barrera, is what sets The Lost and Damned apart.
"I find a lot of the time the stuff you can download to be more of an appendage to a game in terms of, you know, a new area opens up, or you can travel to another island, or something like that," he said.
"You know, it's cool, and it keep fans coming back, but [there's] nothing that's crossed story arcs and that's what we're trying to do, to push this, to deliver a new experience, and I think we've hit it right out of the ballpark."
Look out for our Grand Theft Auto IV: The Lost and Damned review very soon.