Issues booting the game

Since that hardware isn't really supported it's going to be difficult to troubleshoot that issue. Is it just Bloodstained with this problem or can you run other Unreal Engine 4 games on that setup?

Since it's the same exact issue after downloading the files anew, I can only imagine a few reasons. There might be others. Those issues are:

The files located in a steam database are flawed. I don't see this as likely as we might hear more people complaining on more common computer setups.

The files were corrupted or lost during download in similar manners both times. Again I see this as unlikely. There's too many variables to make this repeatable easily.

Your setup (hardware, the way you're running the operating system) isn't compatible with the game. I see this as most likely because your computer isn't being used the way an ordinary user would and the demo is very much a buggy beta version.