A hodge-podge of stories, some solid, some pointless..., many just sorta "meh". Here's a breakdown, IMO:

(13) What if Conan the Barbarian walked the Earth today? A dynamite story, start to finish. Easily one of the best the original What If? series ever produced. 5 stars.

(14) What if Sgt. Fury had fought World War II in outer space? Well hell, I don't know, and this story doesn't make me want to care. This never explains how Earth is somehow 100+ years more advanced than in reality. This just dumps the Sgt Fury mob squad in spaaaaaace.... Gah. 1 star.

(15) What if Nova had been four other people? Another case where I don't care about the "real" Nova. So alternate takes don't mean anything to me. 2 stars, I guess?

{ Intentionally omitted: (16) *Missing in action from this collection* What if Shang-Chi, Master of Kung Fu, fought on the side of Fu Manchu? I assume this was omitted due to licensing issues. Might have been an interesting read. }

(17) What if the Ghost Rider, Spider-Woman and Captain Marvel were villains? The Captain Marvel short was okay. The other two characters (Ghost Rider and Spider-Woman) I've always been completely indifferent about. So remixes of those characters is a big ol' "Meh" for me. 2 stars.

(18) What if Dr. Strange were a disciple of Dormammu? Was never a huge Dr. Strange fan, but this was a pretty great story. 4.5 stars.

(19) What if Spider-Man had never become a crimefighter? A bit of a mess, with Peter Parker turning into a bit of a prick. Perhaps mostly due to showing JJJ as a real human being here, call this 3 stars.

(20) What if the Avengers fought the Kree-Skrull War without Rick Jones? An excellent story, through and through, that does away with the "Rick Jones has one-time-ever-and-never-again super-duper whiz-bang special powers" that was the massive cop-out deus ex machina in the canon storyline. 5 stars.

(21) What if the Invisible Girl of the Fantastic Four had married the Sub-Mariner? A sequel to What If? #1 (where she left due to Spiderman joining the team). Reed Richards loses his fucking mind, his team, his best friend (Ben Grimm), and commits to a path of genocide. Pretty heady stuff here! The fact he does not win back Sue in the end is a huge plus here. Call this one 4 stars.

(22) What if Doctor Doom had become a hero? I enjoyed this quite a bit. 4.5 stars.

(23) What if the Hulk had become a barbarian? Another fairly enjoyable story, though seemed like it could have been expanded to cover the entire span of the issue. I enjoy tacked-on Celestial stories, but seems like that add-on at the back end of these issues could have been reserved for another issue in order to fully tell (and thus properly finish) the Hulk story. All the same, another solid issue: 4 stars.

Overall: 3.5 stars (rounded up to 4 stars due to the strength the Conan and Avengers issues).
adventurous funny fast-paced

Another 3.5, but this collection was noticeably better than the first. Maybe I just liked the stories they picked better? The only complaint was with the last issue in the book. The cover and tag line for it really seemed to miss the opportunity to do more with the Hulk. Instead, they went with a couple forgettable extra stories instead.

I used to buy What If comics in the bargain pile at a place called the Book Attic when I was a kid. They introduced me to the wider Marvel universe. Some of the stories definitely were hard to get through, but others were a lot of fun.