As far as I know, Worms is a normal DOS game, so the only way for that to happen should be a DOS install configured to just auto-start Worms on boot. Which makes sense as a way to keep a kid away from anything that could cause trouble.

I very vaguely recall that there used to be a very few PC games that worked as boot floppies and possibly didn't use DOS at all, but it was a rarity and Worms definitely wasn't one.