There are stories that seem to have sprung fully formed from the mind of its creator and there are those where they seem just made up along the way. Both approaches can work quite well, but Gantz is a perfect example where an initially interesting setup leads nowhere slowly until it ends in an entirely cliched, boring and at times laughable bad alien invasion story.
The setup: people after dying from accidents or violence (self- or otherwise inflicted) reach a room in the city where they died, with a black ball in it, that sends them to hunt down mysterious creatures (who appear human but are something quite different). It’s all rather strange and odd, but halfway into the story it becomes quite apparent that the creator had no clue either what to do with it.
There also appear vampires for not reason somewhat later on. And the whole concept of the black balls and the hunt is rather stupid and convoluted in way that makes everything that happened before both sad and completely gratuitous.
Anyways, if there’s one thing that Gantz is good at, it’s über-gory violence. Even for someone who does like a bit gore here and there, the relentless appearance of death, mutilation and slaughter made me squirm for a lot of the volumes until it got so bad that I was both numbed and appalled at it. That said, it’s never comfortable gore-porn like some comics or movies that provide it but make you laugh at the same time. Gantz never makes you laugh, just disquieted how thoroughly horrifying it is. Maybe instead of thicker skin, it gets thinner with age, but I found a lot of the later volumes repulsive and not in a good way.