Unless I misread something, this is included as 1/3 of Ultimate Comics: Divided We Fall, United We Stand, for the most part overlapping with that story: the fall and rise of America in this crazy Ultimate Universe.
But here, we also get a lot more of the story of Miles and Uncle Aaron. Which is a bit more violent and brutal (and quick) than in Into the Spider-Verse (I think? I might be misremembering), since he’s the main protagonist.
It’s a good early story for a new Spider-Man and oh it hits hard.