Gold Rush mode:
Score points to increase the Gold Rush bar. Once it fills,
Gold Rush mode will start. When this happens your health will fill,
you will be invincible, and many extra fish will appear.
You can collide with normally dangerous objects to get points.
The time that Gold Rush mode lasts varies between the type of
shark being played and accessories that are equipped.
During Gold Rush mode, move quickly and eat everything possible
while avoiding paths that offer less opportunities to score.