SNES Rainbow Road

Rainbow Road is a race course that first appeared in Super Mario Kart, and as a retro track in Mario Kart: Super Circuit, Mario Kart 7, and The Legend of Zelda × Mario Kart 8 DLC pack for Mario Kart 8.

Appearance in Super Mario Kart
Rainbow Road is unique in the fact that it is the only track in the game that is not numbered compared to the others, and thus it is the game's only unique track. Despite being the final track of the game, it is relatively short compared to other tracks in the game and it is also the shortest Rainbow Road to date. It is also the only track in the Special Cup with normal traction. Rainbow Road also lacks rails entirely and has only 90-degree turns. Rainbow-colored tiles cover the track's surface, and the yellow tiles conceal Coins and jumping bumps. This course features Star Thwomps which can, unlike regular Thwomps, wipe out a racer by touch as well as by crushing, unless the racer activates a Star or a Boo.

The track begins with racers taking a turn to the right, where they will find ? Panels to gather items. There are some jumping bumps that might be a hindrance as there is a quartet of Star Thwomps ahead with a very tight space between them for racers to pass, although racers can also pass on the sides of the Thwomps. After this, racers turn to the right again where they can collect some coins, followed by another turn to the right, where there is once again a path with jumping bumps with an incoming turn that might cause racers to fall. After this turn, the track gets narrower and follows a long path where more coins and Star Thwomps are found along the way with another turn awaiting the player. It is here where the track gets even more narrow increasing the risk of falling. Before the final turn, the track splits into two roads; the left side contains coins while the right side has 2 ? Panels, both have a pair of Star Thwomps near the part where these roads merge. Alternatively, there is a jumping bump in the middle gap; if any racers use a Mushroom while they are heading it, they can jump over the gap for a significant shortcut. After the final turn, before the finish line, there is another quartet of Star Thwomps, but this time there is no space between them to pass, with players only being able to pass them by driving on the side or when the Star Thwomps are rising.

Appearance in Mario Kart: Super Circuit
Rainbow Road reappeared in Mario Kart: Super Circuit, as the last track of the Extra Special Cup. The background is from GBA Rainbow Road, but with only the sparkles, foreground clouds, and moon appearing. The track is transparent, but only in that game. The Star Thwomps and jumping bumps were removed, and the music is higher-pitched.

Appearance in Mario Kart 7
Rainbow Road returned again as the last course of the Lightning Cup in Mario Kart 7, being the first Rainbow Road to reappear as a retro track in another Mario Kart (besides its reappearance in Mario Kart: Super Circuit). Even though this track is short, and is one of the shortest tracks in the game, there are only three laps instead of five. While keeping the original layout, the red tiles are now pink, and the turquoise tiles are now cyan. Unlike Super Circuit, Star Thwomps (now with the New Super Mario Bros. Wii appearance) return. They are bigger (which reduces their number in the track, from sixteen to seven), and now form undulations on the track upon landing, which the player can Trick off of. Also, howling noises can be heard near the Star Thwomps. Ramps also replace the yellow bumps, though the first two bumps were removed entirely, and a ramp was added on the inside of the second U-turn, adding a new shortcut (requiring a Mushroom or Mini-Turbo to get across). The gap in the forked road near the end now has two-tile longer gaps at the beginning and end, but it is also seven tiles shorter, making the shortcut easier to use. In first-person view, the player can see through the breaks in the tiles.

Appearance in Mario Kart 8
Rainbow Road returns for the third time in the DLC Pack 1 of Mario Kart 8, appearing as the second course in the Triforce Cup. As a result, for the first time, a Rainbow Road course is not the last track in a cup. The track's layout is similar to its appearance in Mario Kart 7. The colors of the tiles are the same as they were in the original version, but this time, they have a neon appearance, their color pattern is reversed, there are now eight different colors of tiles, instead of seven from its previous appearances (adding turquoise between green and cyan), most of the tiles now flash, and the tiles the Star Thwomps land on are now white. The course itself is also wider. Tiles at the edges of the track now have borders on the outer edges. The forked road is also altered further, with the six-tile gap at the end of the hole filled in, the hole itself two tiles wider, the roads being spread two tiles apart, and the music is a deeper pitch.

The Star Thwomps are the same as they were in Mario Kart 7, but they now have sparkles, a mosaic-like appearance, horizontal rainbow lines running from bottom to top of them, and the rounded Super Mario Galaxy look, like the other Thwomps in Mario Kart 7 and 8, rather than their spiked New Super Mario Bros. Wii look in 7. Additionally, the first two Star Thwomps are bigger. Unlike before, when they start to crash down, they will create rainbow waves above them. Also, when they shake (preparing to crash down) and the moment they land, they make metallic glistening sounds. The waves on the track they create are now bigger, move more quickly, and disappear faster than in Mario Kart 7, making tricks more difficult to perform.

The course now takes place in the sky with the moon visible, just like in Mario Kart: Super Circuit, but it now has color-changing hills that stick above them. Various Toad Houses litter the landscape below the course, which in itself is similar to SNES Donut Plains 3. The starting banner is now redesigned, with the traditional Super Mario Kart colored blocks with a star on top of it; the banner also stands on two walled areas, now making the start the only walled part of the course. Also, when a player approaches a turn, two green arrow holograms will appear behind the turn, and indicate in which direction the player must drive (similar to Super Circuit's new courses). Once the player has made the turn, the arrows will disappear.

Trivia

 * Super Mario Kart composer Soyo Oka considers this course's theme one of her favorite compositions.
 * SNES Rainbow Road has appeared in four Mario Kart games, more than any other track in the series, making it the most used track in the series.
 * SNES Rainbow Road is the only course in Mario Kart 7 not to have a boost pad/ramp, and one of four courses not to have a glider pad/ramp; the others being N64 Luigi Raceway,  GCN Daisy Cruiser, and Rosalina's Ice World.
 * Also, in Mario Kart 8, it is one of the two only courses that does not have any boost pads, glider pads, underwater sections, or anti-gravity sections, with the other being GCN Yoshi Circuit.
 * In Mario Kart 8, SNES Rainbow Road, N64 Rainbow Road, the new Rainbow Road and  GCN Baby Park are the only courses in the game to have the map in different colors instead of just blue.
 * In the Mario Kart 8 official trailer for this course, only 11 characters take part in the race.