It's quite self-explanatory when looking at the provided assets really isn't it ? Models textured to look good without just a single diffuse texture with some faint top-down shading built-in, ending up looking also quite convincing under simple in-engine lighting and shadows. Basically high end PS2 SilentHill/MGS4 or…
You can check his dev blogs on Patreon. He explains he doesn't want to use PBR to distract from the core game development for now. He also says that his photo-based workflow keeps him productive. Additionally, for assets created by freelancers, he bakes down the PBR into a diffuse:…
Well it's not an unlit shader since he uses dynamic lights/shadows. Also on videos, we can see normal maps reacting to dynamic lights. Lambert/Blinn shading/(cubemap reflection) on dynamic objects, most specular/reflections directly baked down into the diffuse map, directionnal lightmaps... It's a mix. We kinda do the same…