Knightmare was a kids show from the 1990's sending a group of four kids to try and complete a quest. One of them would walk through a computer generated dungeon with a massive helmet so they couldn't see anything, while the other three advised and gave directions of where they should walk.
The dungeon was computer generated but there was interaction with real people and things in the game.
It was devious, clever, 4th wall breaking and absolutely rock hard. Only a few teams ever managed to complete the game, but its a complete cult classic.
And they are going to do a one off special as part of Geek Week on youtube.
Oooooo Nasty.