I read it as the graphic novel. Blew me away at the time, but, as said, certain aspects of it don’t hold up well for me now. Totally convinced that the change they made in the film, at the end of it, by losing the squid, worked far better than Veidt’s original strategy.
Similar limitation in that without the periodic reappearance of Dr Manhattan and further associated destruction, the mutual, instinctive huddling together for protection by humanity as a whole against a classic shared, Jungian, primal fear threat would dissipate and not stand the test of time. I wasn’t quite as much into this kind of stuff as a kid or twenty something.