Unlock '1984' (Konami code + secret date) (Easter Egg)
At the 'Press Any Button' title screen enter the Konami Code; a secret input field appears — type 06061984 to unlock the black-and-white 1984 Electronika 60 style. (Also unlocks automatically if you play on June 6.)
Up,Up,Down,Down,Left,Right,Left,Right,B,A then 06061984
Enter the Konami Code at the 'Press Any Button' title screen, then type the code into the secret input field that appears.