Sorry for the late reply, but if you're talking about the paid release, its probably lack of memory or video-card conflict.
Also, the loading screen seems to freeze during the loading, but its only a bad feature that I'm about to correct it.
The demo release just have a lot of issues with memory management that was corrected on first release.
- Required ideal system memory: +8gb RAM
- Required ideal videocard: GTX 1070 or better.