The third challenge requires one to play Halliday's favorite Atari 2600 game, in a castle on Planet Doom, which Sorrento has protected with a force field. Parzival recruits other OASIS players to help them attack the 101 forces around the castle.
Art3mis was able to deactivate the force field, allowing Parzival and the other recruits to attack the forces of 101. Sorrento decided to use a bomb that will erase all the avatars in the OASIS. However, thanks to a coin given to Parzival, he had an extra life and he played the Atari 2600 game.
Parzival was able to finish the game and got the crystal key, the third key. He was able to unlock the three gates and Halliday gave him the Easter Egg which will give him the total control over OASIS