Virtual Relationships: Gillian Cross, New World. Oxford: OUP, 1994.
Miriam and Stuart are chosen "randomly" to test a computer game. There are oddities from the beginning. Stuart is a nerd, but Miriam isn't. And when they first go into the game Miriam's "gun" is stolen by a hand emerging from a bush.
As the game goes on, both children are puzzled by the relatively easy levels in the game. but the apparently disproportionate fears. Then they (separately) realise that their own personal phobias are being targetted.
Meanwhile, there is a lot of personal and family stuff going on for Miriam. Usually (as you all know by now) I hate this because it becomes the purpose of the text, but Cross is a smarter author than that, and the personal stuff becomes key to what's happening in the game.
Miriam lives with her father, step-mother and two siblings on a house boat. It's driving her mad. Laura is an invetterate therapizer and Miriam has no emotional privacy. It's so bad that she has been driven from her best friend Connie, who is a questioner of a different kind, to Debbie the facile, because with Debbie she can relax. At least part of what will happen is Miriam calming down enough to be Connie's friend again.. And Connie will help Miriam with her investigations.
Stuart is a standard nerd, bullied at school. But it turns out that he also knows a kid called Will. Will we've met "hacking into a game" at his father's behest, to somehow solve a problem that will let his father's company gain an edge in the market. But when Connie chases the woman who liases with Stuart, it turns out that she is also liasing with Will. Who is the son of Hesketh the computer programmer who has designed the game that Stuart and Miriam are playing.
So when we do get to the personal stuff we discover that Hesketh has betrayed his son Will by encouraging him to play to his own "dark side" as a torturer in the game. That Miriam's father didnt' give her secret phobia away but that Hesketh had been there on the night of one her childhood nightmares and had betrayed Will doubly by comforting her in the same way he comforted Will.
What I liked is that although it was important that the prtoagonists sorted out their personal stuff, the trajectory was towards the world: so Miriam learns to live with Laura, but by exerting her adulthood, not by complying. And her first real adult move is to insist on a public friendship with Stuart.
Also good is that the game genuinely required problem solving which we got to see, and the plot itself became a technological problem to unravel (there is a nice bit when Will records the "squeaks" on his screen and gets them to play slower, to discover that they are actually voices).