What's really missing is an open source "bring your own engine and asset pipeline" editor tool. Game editors have pretty much arrived at the Unity data model and editor workflow (game object outliner to the left, scene view in the middle, property panel on the right, asset panel at the bottom, plus custom panels). The Unity Editor and asset pipeline is hackable enough to use it as editor for another engine, I did... - Source: Hacker News / 9 months ago

There are two primary contenders to replace the BGE. One is Armory3D (https://armory3d.org/) It has a ton of potential, and outputs to multiple formats including web. But it's a one-developer show and it's been really inconsistent. I taught a class on prototyping 3D games with it, but updates are slow and inconsistent, as is the documentation. Too bad, because it's a promising project, with a blueprints-like... Source: about 1 year ago

Armory3D is also interesting, not a fork of the original BGE AFAIK but integrates with Blender. Source: over 1 year ago

Another game engine blender https://armory3d.org/. Source: over 1 year ago

I don't know what it's worth, but Armory3D is also an engine built with Blender : https://armory3d.org/. Source: over 1 year ago

I leave this little thing: https://stride3d.net. Source: almost 2 years ago

You can have a look at Stride - you also write games in C#, and it's open-source entirely. Its documentation has also some nice comparison of Stride to Unity, including some guidance about porting Unity code to Stride: https://doc.stride3d.net/latest/en/manual/stride-for-unity-developers/index.html. Source: almost 2 years ago