That era or design is long gone. like even PS2/GameCube have firmware to let you change settings/manage memory cards without game disk. With the variety of hardware you can connect means you need to separate the software layer that talking to hardware's from the game, thus the operating system. You can turn on GBA for example without a cartridge, but it would kinda just stuck. That's like the last boot to game device I am aware of.

Would a game that is essentially a micro Linux distro count? I feel that should be pretty doable as a bootable USB stick or CD.

If you did it that way you'd have to bundle the Linux kernel plus graphics drivers at a minimum. But I wonder how much of the OS you could avoid having. Certainly you wouldn't need a Desktop Environment. I wonder if you would need something like X or Wayland or if you could get away without that (to run games built in a normal-ish userspace way). I guess finding the minimal environment for SDL would be a good starting point. That sounds like an interesting exercise for sure.

Although something like that probably isn't as pure as you're looking for, it would be pretty cool to do anyway. Maybe we should start a club.

Is the technical distinction of booting as an OS an important one, or are you just interested in games that boot up very quickly, such as in the cartridge days of the N64 and so on?

I'll admit, I still think games could do a lot more on the latter. It's still a tragedy to me that so much wait time is devoted to the company logos for things like Speedtree or Criware.

This would be a good demoscene category. Sadly it looks like pouet.net doesn't have a "platform" category for raw x86 (I think some of the DOS entries will be this, but not all) and I only saw one entry for x86.

At the end of the day: I think MS-DOS is a more attractive target than raw x86. It does a few things for you, but then mostly gets out of the way if you don't want to use its features, and has better accessibility (thanks to DOSBOX) for most users.

I've been working on an 8088-class project PC and equipped it with:

• 128k of flash ROM
• Custom firmware to use 90k of it as a bootable "floppy".

This made it possible to boot straight to DOS games.