I was gonna do a long review of Gamma World, but, well, here. I liked the design of the book much more than that guy, but his comments on the mechanics are right on target.
The community rules are both really inspiring and kind of disappointing. The idea of using PC stats to represent a group of people is great; I can’t remember where I first saw it (might have been Vampire, actually) but this is a really good implementation of it. Except that several of the stats have no game effect, and there’s no meat behind most of the ratings — no explication of what they mean.
I see, in Gamma World, a pretty stark example of the conflict between the relatively rules-loose style of White Wolf and the number crunching of D20. There’s more room for jazz in the Storyteller system, partially because the system is looser and partially because the expectations of the fans are different. D20 games need mechanics that interlock and function predictably. Gamma World doesn’t really have ‘em.
And it’s a shame, because it’s a really inspirational book. The updated background, involving a failed Singularity, is very good. It just needs a better ruleset.