Tip: Make sure that ALL exit-enabled pipes, doors, etc. have a screen exit defined, or they'll take you to Level 0, the "endless" bonus game. Unless Start+Select is enabled, the only way out of it is to reset the game.
This star, inspired in the Super Mario Land 2, moves following a "infinity" curve. It's indestructible unless hit while Mario has star power. If the extra bit is set, the star will explode after a set amount of cycles.