I played a game like this before. The whole journey took about 6 hours to complete. Realizing who I was interacting with was one of the best moments I've had playing a video game.

Edited to add: I think I've played two games where the bots turned out to be people. The second game was much longer, and I never finished it - I only learned that the bots were people from a YouTube video later on.

This is a good idea, and it is under-explored!

Spoiler: VGhlIGdhbWVzIGFyZSBKb3VybmV5IGFuZCBOZWlyOiBBdXRvbWF0YS4gVGhlc2UgZXh0cmEgY2hhcmFjdGVycyBoZXJlIGFyZSBiZWNhdXNlIEkga25vdyB5J2FsbCBjYW4gcmVhZCBiYXNlIDY0IGluIHlvdXIgaGVhZHMu

Riot Games did this one year for April Fools in League of Legends. Normally you can play a 5v5 match against other players, beginner bots, or intermediate bots.

For April Fools, they rolled out "Advanced Bots", which were actually another group of 5 humans, but with their username replaced with "<Character> Bot". Word got out pretty fast, but it was super funny queuing up for a game you'd normally win easily and being surprised at how smart those bots have gotten...

I don’t remember which iteration it was, but there is a game in the Dark Souls series where one of the bosses is a player that invades your game to be the boss.

It’s a cool twist on the PvP of the game where you can be invaded by a player at almost any time but you can usually opt out of the PvP but this particular encounter is needed to progress.

So these games are versions of the book "Ender's Game"[0]?

[0] https://en.wikipedia.org/wiki/Ender%27s_Game

And much easier! See, this is why a team of people is better than just one person with tunnel vision.