I play Black Mirror (the new one) on Linux Mint 18.3 and all is fine.

But one little thing is curios:
If the game starts, i see an nice ingame mouse cursor.
But after the first short logo movie the cursor changes to the system one.

What's happend here?

There is no option (or cfg-file to edit) to change that.
I don't have such problems in all other linux-based games with unity.

If that is is the only problem you have with the game, consider yourself lucky and just play for four hours until it ends.