While for other platforms of that era (primarily, Amiga), putting a game on a bootable disk was quite a normal practice, this approach never taken off on IBM PC. Why not?
I do remember people having multiple menu-driven autoexec.bat and config.sys configurations because one would have to boot MS-DOS with only the bare minimum to satisfy the requirements of some memory-demanding games. Since MS-DOS was by and large a single-task operating system, wouldn't booting a game directly from disk be more efficient than going through all the hassle of finding a working configuration of HIMEM, EMM386 and whatever else?
Even when Windows took over, would there be benefits for a demanding game to have full control over the PC resources as opposed to competing with a multitude of random background processes potentially spoiling the smooth FPS?
I understand that games in such a scenario would have to include a minimalist operating system, but I guess a carefully tuned Linux kernel along with drivers for all the popular graphics cards would be enough? This is for the Windows era, that is - for MS-DOS, I guess all the essentials games of that time needed were available directly from BIOS (well, file system support could have been an issue but I recall Amiga games of that time used to read the game data directly from sectors on the disk).