-1 for missing the whole point of "Doom running on..." projects. They're funny or impressive when run on hardware never meant for it: calculators, 286s, pregnancy tests. Not a tiny processor you custom built just to run it.
And you're saying it's not impressive to build a tiny custom processor and run it on a Christmas tree ornament? Tell you what, you build something like that and then I'll consider what you said valid. And in all those other examples you listed, Doom is running on a tiny processor so I'm not sure what you're even on about. And as far as I know, Doom isn't supposed to run on a Christmas ornament. You're just being needlessly critical.