Doh :-( Would you mind giving a try with the wine emulator ? It makes a lot of games run flawlessly on Linux! I can give it a try if you have a demo/alpha build available.
I just completed the demo using Wine. The only issues I found was that trying to use Alt-Tab made me unable to click on anything after and had to kill the process to exit the game and sometimes certain screens only rendered a black screen with a pointer. When this happens just press "enter". Other than that demo ran fine. I enjoyed it.
AMD Ryzen 5 2600X | 16GB DDR4-3000 CL15 | MSI RX 580 8GB Gaming X | Mesa 18.3.3 | Manjaro Mate | Kernel 4.20.11-1-MANJARO