A lesser-known Easter egg, Gurin and Malon can give birth to a smaller penguin (either pink or green) if they meet 16 times and their meeting time is between 1-3 seconds.
Continue
At the title screen, after a game over, hold A + B and press Start.
Hi-Score
If your score is higher than 30000 pts, press Select button after you die - you will be able to enter your name on the list of the best scores.
Love Story mode
Press and hold the A and B buttons on both controllers and press Reset. If done right, the game will change to Love Story mode.