Credit goes to Jimmy_B for finding this Rocket League easter egg, which is currently only found on the PC version of the game. You have to have the game on the PC and have a PS4 DualShock4 controller plugged in. If you enter the Konami code while the game is starting up (up up down down left right left right O X) then hitting the ‘options’ button when the game is fully loaded, you get the easter egg.