https://www.phoronix.com/news/Coreboot-4.17 (June 2022)
Coreboot developers are releasing Coreboot 4.17 today with various new motherboards supported, support for GRUB2 atop SeaBIOS as a payload, and various low-level code improvements too. Plus Coreboot 4.17 brings the "coreDOOM" payload -- yes, it's possible to get the game Doom running atop this system firmware.
Hmm no boot drive found, press F1 to play Doom instead!
Kinda like the Sega Master System. If you turned it on without a game and pressed UP + A + B at the screen telling you to put in a game cartridge, it launches a game where you guide a snail through a maze:
I would much rather have a little diagnostic and data recovery OS in the firmware with drive mounting support, a file manager, and USB mass storage rather than Doom or Tetris or whatever the hell. Playing Doom from firmware is a neat proof of concept, but won't help anybody un-bork their OS install.
There were some motherboards that had something of that nature (Asus had ExpressGate IIRC) but they were all hilariously incomplete because they didn't realize how useful as a diagnostic thing it'd end up being and tried to sell it off as a "quick boot" thing.
As a cool side project I could see someone developing it. But I don't think any companies would put money into it. It doesn't add a huge amount of value to the product.
Actually it could detract value.
A consumer's computer's hd get corrupted. They're now playing space invaders. That means they're not buying a new computer.
For some people it works just be a delay, others may just resign themselves to play space invaders for eternity.
You could set up a ROM drive with like 128k, and that would be enough to emulate a floppy, boot DOS, and load an classic off-the-shelf game.