Nearly two dozen CD-ROMs aimed at pre-teen girls will be released later this year by companies with names like Girl Games, Her Interactive and Purple Moon. It's a market that has been all but ignored in favour of the seemingly bottomless appetite of boys and young men for so-called twitch games like the bloody light-speed shoot'em ups Quake and Doom.Count Laurel of Purple Moon, believes that the biggest mistake games developers make is misunderstanding why girls don't like Doom and other so-called boy's games.It's not just that most girls are appalled by the brutal violence - they certainly are - but also that they resent the assumption that these games are too difficult for girls to play. Girls don't think boys games too hard; they think they are stupid. Boys like overt competition, violence and mastery for their own sake. Girls, by contrast, prefer covert competition, intricate narratives and group efforts based on complex social hierarchies.