Well, I was thinking something like a single-player game where you are the spider and, through the course of whatever the gameplay entails, you struggle as a spider to stay alive. This could perhaps build empathy for spiders and cause people to think twice before casually killing one. So beyond conquering arachnophobia, what if we can give people a positive affinity towards spiders?
A multi-player spider game sounds potentially terrifying.
But a regular and 'by design' aspect of a game, presumably online?
Dunno if I, as an arachnophobe who plays plenty of games online-trust griefers not to ....well grief with that kind of power, heh.