This build includes experimental AMD FidelityFX Super Resolution (FSR) support. Since it's experimental (for now at least), it might not work on all games.
FSR is disabled by default and can be enabled with WINE_FULLSCREEN_FSR=1 environment variable. The sharpening amount can be adjusted with WINE_FULLSCREEN_FSR_STRENGTH=5 (from 0 to 5; 0 is the maximum amount of sharpening, 5 is the minimum and is the default value). Don't forget to enable fullscreen in game settings and choose lower resolution.
Here is my FSR comparison in The Witcher 3, open the screenshots in full size and you will see the difference. I used WINE_FULLSCREEN_FSR_STRENGTH=3 in this comparison.
And here is comparison in Kingdom Come: Deliverance, the difference is even more noticeable here.