The Black Mesa team has announced that Black Mesa: Xen will release in Q2 2019. In order to celebrate this announcement, as well as Half-Life’s 20th anniversary, the team has also released a new trailer that you can find below.
As the team noted, the months until the game’s release will allow it to finish Xen to a place where the entire product is stable, smooth and fun. Almost everything is design locked and functioning as intended right now and the Xen part will last around 6 hours (longer for those that want to explore everything).
Furthermore, the levels and design for Xen are largely original work (with cues taken from Half-Life), rather than just simply a remake of Xen. In other words, there will be some level differences between these Xen levels and the original found in Half-Life. Also, the team has added new levels in order to extend its length.