Update: Binding of Isaac creator Edmund McMillen has tweeted out a call to the developers of Antibirth offering them access to tools to get the expansion better integrated with Afterbith and the upcoming Afterbith+. This most likely quells any fears that Antibirth will be seen as problematic, and we have hope that the best version of Antibirth can be out sooner rather than later.
https://twitter.com/edmundmcmillen/status/810209436211912704
The original article continues below.
Despite some stiff competition this year, I think it's safe to say that The Binding of Issac is still safely among the top of the roguelite genre. With a new expansion releasing early in 2017, it seems that fans of the basement crawler have plenty to celebrate. However, what if you're impatient? What if you want new Isaac and you want it next week? Well, if you've already read the headline, then you know that you'll have the opportunity for some new Isaac goodness next week when The Binding of Isaac: Antibirth is released.
The work of a core team of four fans over the last two years, Antibirth is about as professional as unofficial content can get. The list of content rivals the size of the official Afterbirth expansion, including an entirely new chapter, two new characters, over ninety collectibles and 18 trinkets to add to the mix. There are also new bosses and enemies to face, and you'll face them in over four thousand new room types. If that wasn't enough, the Antibirth team have also introduced true co-op to the series for the first time with a few tweaks, allowing for two Isaacs to play instead of one Isaac and one baby guardian.
If you own Afterbirth, you'll have to choose between that content and the content included in Antibirth. It will also not be compatible with the upcoming Afterbirth+ expansion. However, save games will not be affected by the mod and the team is looking into integrating all of the expansions together as a part of future updates to the mod. The release will also only be available on Windows due to the way it was built, leaving Mac and Linux players out in the cold. If you're interested in warming up for more official Isaac, Antibirth will be released on December 20th over on the team's website.
TechRaptor has reached out to Nicalis for comment regarding the unofficial expansion and will update if we receive a response.