Debian 9 x64 Mate
Blender 2.79 5bd8ac9abfa

By doing something like:

import bge
own = cont.owner
blendmat = own.meshes[0].materials[0]

print(blendmat.emit)
blendmat.emit = 2
print(blendmat.emit)

The material emit doesn't change.

Open file, run engine, look at the console.