[gtop3]

It's also the described metaverse evolution in Ready Player One, which is six years older than Fornite. It felt like an obvious and pre-existing idea when Ready Player One was published, so I wouldn't be surprised to hear about older incarnations.

[vidarh]

Tron? Not quite the same, in that Flynn didn't enter voluntarily and it's explicitly unexpected for a human to enter, but the merger of games with a virtual world is there.