It's not for little kids, though. Lots of blood and gore and death. Especially death.
I think there was a meaning to it, but I don't think I got it. Possibly something a) about human nature, and b) working together?
Interesting how all of the people GANTZ took saw the train accident.
Connection between old lady and GANTZ...? I don't know. Ending leaves a number of questions, actually. Like... what happened to our main character? We saw GANTZ go poof, kinda, but is it the end then? And what was GANTZ's purpose? What about the others that died along the way? Are they going to come back?
But yeah. That anime series left a number of "........wow." moments. Or "Hmm, huh... Owww.. head hurts from thinking." Yeeeeah. I'd recommend it, for human behavior studies or something, as there's a lot of that.
Most interesting point: something along the lines of "Everyday people are killing~ why does it matter if I kill some more? I don't kill as many as wars do." linked with, "Be careful. The most dangerous are humans."