Indie developer Edmund McMillen is working hard at the first downloadable content for The Binding of Isaac, along with the 3DS port of the game. He's shared some more details now on the current status of the port, new items coming in the DLC, and how the deliberate pace of the game is so important to its design.

"It's crucial to the game's design for [the DLC] not to be longer than the game is now," McMillen told Gamasutra. "It can't be longer. There's a lot of elements to its design that won't work, and it will just become boring, or drawn out, or too hard."

That bullseye of playtime is an hour, which will be facilitated by chapters with alternate paths. "What I've shown is the cellar, which is an alternate to the basement," he explained. "So you could start your game, and it might be the cellar 1, which has different enemies, different rare rooms, different bosses, different random happenings that are going to be new to the mix. Then the next level you might be in basement 2, or maybe the next level you'll be in cellar 2. It'll just choose randomly from those."

He says he wants to "trick" himself with the randomness, alongside the new loot. The game adds roughly 50 items and 20 trinkets, but Wrath of the Lamb relies on the random element to keep it fresh for multiple playthroughs.

As for the proposed 3DS version, McMillen vaguely says he can't talk about what's going on behind the scenes, but a lot has yet to be determined. "I don't know if it's promising or not honestly, it's still up in the air. All I can say is, it's being discussed in-depth." He says most people involved aren't sure "how to take the game."