Grudgingly, I admit this would be darker than our current timeline. But only barely.

There are some issues of What If? that are awesome, even inspirational; and then the vast majority read as Worst Case Scenario: the Series. Today's book may not be the earliest example, but may be the epitome: from 1982, What If? #32, "What If...the Avengers had Become the Pawns of Korvac?" Story and layouts by Mark Gruenwald, finished art by Greg LaRocque, with plot input by Peter Sanderson and a small platoon of inkers!

Even though I'm not sure I had read an Avengers comic at that point, I remember seeing the old Bullpen Bulletins page mentioning the conclusion to the Korvac Saga, which ran a then-unprecedented ten (!) issues, from Avengers #167 to #177. And there's a pretty good recap of it here, before things go off the rails.

If Korvac's beloved, Carina, had not shown doubt in him at a crucial moment, Korvac would've gone on to not only destroy the Avengers, but the entire universe! It's kind of a downer. Early in his campaign to universal armageddon, Korvac boxes out Zeus and Odin from avenging their sons, and goes on to close access to the universe from other dimensions...is that Jesus on the bottom there? (No, it's Aquarian. Probably? Damn, that earth is in trouble.)

If you've read a lot of What If? you may remember the brief coda in What If? #43, where after being kicked out of the universe by Korvac, Phoenix, Dr. Strange, and the Silver Surfer return to find it destroyed! Also a downer, but that issue has a Sienkiewicz cover for Conan, trapped in the 20th century! Conan stabs Captain America, but that story's way more uplifting than these two, trust me.

Y'know, I'm always surprised when I see Gruenwald's name for art credits; I always forget he did pencils (or at least layouts) for the first Hawkeye limited. And looking at that last page again, I'm almost positive I read this off of the spinner rack when I was 11!