Update on this, I had a download of Flattened.rar in an itch file, unpacked it and it was missing a file, something like resources.resS
I have no idea if it has something to do with the game on a white screen.
Something else too is that I uninstalled and then installed Flattened again, tried running it up again, and the screen was grey, but then white and... forever unusable.
Deja vu... nearly forgot to mention its only a data pack, no game