I've wanted to read this since the first time I played the Sega Genesis game based on it. And while it wasn't the best thing ever by any means, it didn't disappoint.
Cletus Kasady, a.k.a. Carnage, breaks out of a mental institution and takes with him another psycho supervillain named Shriek. They become a twisted, abusive couple (kind of a Marvel equivalent to Joker and Harley Quinn, but with powers), and quickly pick up a few lackeys that they treat as their "children" in the form of the Doppelganger Spider, Demogoblin, and Carrion. Spider-Man tries to stop them, and ends up teaming with Venom and a long list of other heroes and antiheroes in order to take them down.
There's an ongoing sort of debate between the various heroes and antiheroes (and mirrored by a few of the non-powered people in the story) about how far the heroes should go to to stop the villains, i.e. should they kill Carnage or capture him and turn him over to authorities again? If the hero doesn't kill the villain and the villain kills an innocent afterward, is the hero to blame? The story examines these questions, and even though Spider-Man reaches the only conclusion he ever could (especially in the time period this was published), it's the most interesting part of the story. The battles are fairly standard comic book fare, with lots of still action poses, "witty" banter between the characters while they fight, and a whole lot of inconclusive battles that feel like they exist solely to pad the page count until the predetermined ending time.
I can't help but compare this to the video game. The cutscenes in the game (at least, the ones I remember) consist of panels lifted directly out of the comic, but rather than the rest of the panels they're strung together by a beat-em-up game where Spider-Man or Venom beat up dozens of thugs and then sometimes the supervillains. None of the thug designs, even the ones that are boss characters, bear any resemblance to anything in the comic. A lot of the nuances of the story didn't translate to the game. But on the other hand, I found myself practically humming the game soundtrack while reading the comic. I can't remember the ending of the game, but I feel like it diverged somewhat from the source material, or at least it didn't cover all of it.
Also, there's a random story with Spider-Man, the Punisher, and Sabertooth stuck in the end of the book that's not connected to anything else. I know comics used to do that back in the day, but I had thought it was pretty much a thing of the past by the 90s.
Anyway, overall this was a fun read, but not one I think I'll need to read again. I probably will dig out the game again sometime though. The story isn't as good as the comic, but the game play and soundtrack help make up for it.