We've upload a package for Unity! Please download "Japanese apartment Unity-URP.zip" It's made for URP. If you're using another rendering engine, you have to convert the materials.
As for baked lighting, the meshes have a few overlapping UVs which is a common technique for low-poly and small texture sized PS1/PS2 games. So I think that's creating the problem with baked lighting. In Unity, did you already try turning on "generate lightmap uvs" on all the models? If not, that may fix it.