FreeGameDev

Just to share some interesting new game related tools for Blender:

https://github.com/Moguri/BlenderPanda
Integration of Blender with the Panda3D engine, i.e. use Blender as the editor/SDK for Panda3D games.

https://matt-lucas.itch.io/level-buddy
https://github.com/jpcy/bfg_forge
Doom like level editor integration into Blender, to very quickly make nice FPS maps.

https://chemikhazi.itch.io/sprytile
https://github.com/Sprytile/Sprytile
3D sprite-tile low-poly editor. A bit hard to describe

Any other cool projects to share?

Any other cool projects to share?

Only a vague idea for a workflow that might be supported by a plugin... which may or may not be feasible so don't get your hopes up. Also, I'm not even that much interested in it myself, so I'm probably not going to create a blender script for this myself.

Remember Spritelamp?

youtu.be/fy3FvPg01w0

Instead of drawing 4(or more) direction light maps, maybe it's possible to draw a greyscale heighmap version of the image. Maybe it's easier or even faster. I'm no pixel artist and it sounds pretty hard, but so does drawing 4 direction light maps.

Now in Blender: Create a new plane and scale it to the proportions of the image. Subdivide it into the x and y resolution. Apply a displacement modifier, using the drawn heighmap.
For the last step, bake the maps you want to another plane with the same proportions and size. Tadaa! Normalmap.

Just a thought for now, so there might be a number of problems in it.

Maybe a bit more than an integration, but this early alpha of a new unofficial game engine for Blender looks great:
https://youtu.be/2-xkLH5FjPw

http://armory3d.org/
https://github.com/armory3d

Another open-source game engine that seems to allow working in Blender as it supports natve .blend files:
https://github.com/etodd/deceiver

https://github.com/joshuaskelly/io_scene_bsp
Load Quake maps directly into Blender