UPDATE 3/9/18: Binding of Isaac creator Edmund McMillen has shared more details on the mysterious The Binding of Isaac: Repentance, which was teased last week.
Repentance will be the third paid expansion for Binding of Isaac: Rebirth (it's also received five free mod-based Booster Packs), and is, according to McMillen, both "pretty beefy" and the final DLC for the game. This certainly isn't the first time an Isaac expansion has been described as its last, but McMillen did add, "for real this time".
According to McMillen's tweets on the matter, Repentance will be based on the extremely well-regarded, and sizeable, Antibirth mod for The Binding of Isaac. It's being tweaked to "make it canon", and will feature "a ton more content that will make you sh*t your butts!". This extra content will include "new cutscene(s) and story bits" as well as, inevitably, "more poop".
Additionally, regular Binding of Isaac composer Ridiculon is creating a new soundtrack for the Repentance DLC "so it all feels cohesive and part of the official game". However, Antibirth's original composer, Mudeth, posted that they're also "finishing a full replacement soundtrack separately, although it'll have to be modded in I guess."
McMillen is working alongside Antibirth's original creator Vinh (who was also heavily involved in sprucing up the game's Booster Pack content for official release) to create Repentance - which doesn't, at present, have a release date.
ORIGINAL STORY 30/8/18: DLC? A new game? Nobody quite knows for sure, but one thing's for certain - a new Binding of Isaac instalment is on its way in some form.
The announcement came from developer Nicalis, which tweeted a short teaser trailer in the dead of night (in America, at least). Pretty appropriate for the creepy game.
The short video suggests we'll hear more about Repentance at PAX West, so keep an eye open for more developments over the coming weekend.
The Binding of Isaac - if it passed you by - is an indie roguelike where the player must guide a young Isaac through a basement filled with monstrosities. It tackles difficult themes such as religion and child abuse, and received praise from critics for its treatment of these topics.
The game was originally released in 2011, but has received DLC expansions before, such as Wrath of the Lamb and Afterbirth+ for The Binding of Isaac: Rebirth. The latter was released last year, and brought the game to the Switch. It's easy to imagine the new addition, whatever it may be, will likely be released on Switch as well as PC, PlayStation and Xbox.