I've read the criticisms here, but well, as someone whose first computer was a C64, this is cool as hell.
Like, what?!
On an 8-bit, 64Kb, ~1MHz CPU!
Amazing.
Sure, there are too many caveats, but this isn't really about making this a viable modern alternative.
It's just about, well, being very cool? Nostalgic!
And in that, I think it succeeds.