There are secrets that can be triggered by pressing the Start button rapidly on the Beginner, Advanced, and Expert courses:

•On the Beginner Course, stopping at the Finish line and pressing Start rapidly will cause the bulletin to flash various hidden messages. Despite being approved for all audiences, one message states "Go to Hell".
•On the Advanced Course, during at least the third lap, when you reach the giant red skeleton spider, rapidly pressing Start will cause a spaceship attacking the spider to fire lasers at it. This is the only one of the three secrets that can be triggered in the MIX version of the course.
•On the Expert Course, near the Start line, there is a set of five industrial fans that will spin faster the more you press the Start button. If you hold the Start button for the entire first lap, on the second lap when you return to the fans, they will be spinning so fast that they will actually fly off of their hinges and out of the course.