Seems simple enough. I assume you can just swap the background.png file to get something else?

XcQ - three characters that instil a sense of impending memeage like no other

would better be project’s github page

Oh man. I remember that screen. It happened when I installed Windows 10 on my MBR partition table back then. Shit messed up the partition table and I had to manually tell GRUB my Linux partition to boot. But I eventually fixed it by reinstalling it.