Rainbow Course

A Rainbow Course is a type of bonus level in each world of New Super Mario Bros. 2. It occupies the starting point on the world's map. Each time a Rainbow Course opens, the player has one chance to play it after entering; it closes when their character exits by falling off. Flying Gold Blocks do not appear in Rainbow Courses, and inventory items cannot be used.

The player can open a Rainbow Course by finishing a level when each of the last two digits of the Time Limit matches the number of the current world (World Mushroom being counted as "7", World Flower "8", and World Star "9"). The appearance of fireworks and a rainbow, as the Super Mario Bros. "Course Clear" theme plays, indicates success. Additionally, all Rainbow Courses open when the player receives a SpotPass message from the game, regardless of what the message is about.

At the beginning of every Rainbow Course, Mario must enter a Pipe Cannon to be launched into the titular rainbow-themed Coin Heaven. These areas autoscroll or take place on a moving Lift. They contain large amounts of coins, Roulette Coin Blocks (including a larger one with a maximum result of 100 coins, instead of 50), 10 Coins, and one giant coin each (aside from those in the Roulette Coin Blocks). Some Rainbow Courses have a Red Coin Ring that places a Gold Flower in the Item Storage if all Red Coins are collected. At the end of the course, the player character is forced to fall off due to a large gap (in autoscrolling courses) or an impassable wall that the Lift recedes into.

The music heard in Rainbow Courses is an arrangement of the New Super Mario Bros. Wii Coin Heaven theme. It has different instrumentation and is a semitone higher than the key of the original theme.

New Super Mario Bros. 2

 * European Website bio: "New Super Mario Bros. 2 features more than 80 courses packed with classic Mario action – some of which are even rainbow themed!"