So glad to see this here. I live in the boston area, and have been attempting to acquire appropriate cannons with which to play. If you're in the area and wish to join me in my mad quest (in either finding the cannons, or playing), message me (@vonkow on twitter works too).
There's also: "It can be played by boys of every age from twelve to one hundred and fifty—and even later if the limbs remain sufficiently supple—by girls of the better sort, and by a few rare and gifted women."
The condition on which boys can play it is that their limbs are supple. Girls can only play it if they are of the better sort, not to mention women - only a few rare and gifted can play it.
It looks like there are some underlying assumptions about the abilities of boys and women. Hm... nope, they do not look much like feminism to me but what do I know.
As I said, if you put the comment in context, the fact that they are even suggesting that some girls might like it is a little bit of emancipation.
Full women's suffrage was still 15 years away, the feminism movement over forty years away. The suffragette movement was at its most active at this time: this book was published the same year that Emily Davison died trying to throw a suffragette banner over the King's horse.
HG Wells was probably a feminist: he certainly had affairs (and fathered children) with a number of prominent feminists of the time. He was certainly a socialist and a member of The Fabian Society: his books tackle many of the political problems of the time.
Once you factor this in, the meaning of "the better sort" of girl and "rare gifted women" becomes far more interesting.
"The better sort" and "gifted" could mean those women with the will and bravery to ignore the social stigma rather than the intelligence that you are implying.
It read to me like he was insulting women who choose to not act this way rather than implying the gender was genetically unable to do so.
This reminds me of a similar game called Lego Wars that my friends and I used to play in middle school (I downloaded the rules off of GEnie):
http://mama.indstate.edu/users/sean/legowars/wars.htm