The Nintendo Switch has just celebrated its two year anniversary and the current best-selling game on the system is a port of a game that was released in 2014.

The Nintendo Switch has an incredible library of games that includes the likes of The Legend of Zelda: Breath of the Wild, Super Mario Odyssey, and Super Smash Bros. Ultimate, yet the best-selling game on the system is Mario Kart 8 Deluxe with over fifteen million copies sold.

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The high sales figures of Mario Kart 8 Deluxe are no fluke, as the series has consistently been hitting the top or second spot on the best-selling games list of every recent Nintendo console. The Pokémon and Super Mario Bros. series may have a higher profile than Mario Kart, but it's the racing game that is really bringing home the bacon for Nintendo.

Mario Kart 8 Deluxe is following the trend set by its predecessor, as Mario Kart 8 was the best-selling game on the Nintendo Wii U, with over eight million copies sold. Mario Kart 7 is currently the best-selling Nintendo 3DS game with over eighteen million copies sold and that record isn't likely to be broken anytime soon.

Mario Kart Wii was the second best-selling game on the Nintendo Wii with over thirty-seven million copies sold, while the best-selling game (Wii Sports) sold over eighty million. The fact that Wii Sports was a pack-in game means that Mario Kart Wii's numbers are still very impressive.

Mario Kart: Double Dash!! was the second best-selling game on the Nintendo GameCube with over seven million copies sold, where it sits just behind Super Smash Bros. Melee in terms of sales. Mario Kart 64 was the second best-selling game on the Nintendo 64, beating both Goldeneye 007 and The Legend of Zelda: Ocarina of Time, while only losing out to Super Mario 64. 

The only systems where Mario Kart hasn't hit the top two spots are the Nintendo DS (where Mario Kart DS was the third best-selling game), Game Boy Advance (where Mario Kart: Super Circuit was the fourth best-selling game), and the Super Nintendo (where the original Super Mario Kart was the fourth best-selling game.)

So, what is it about the Mario Kart series that has made it so successful compared to its contemporaries?

The best way to describe the success of Mario Kart is that it can be enjoyed by anyone of any skill level and it is still just as great as either a single or multiplayer experience. A player can have just as much fun clearing all of the stages on their own as they can when racing against other people. The series also lacks any kind of objectionable content, making it the safest purchase possible for parents, unless you count the amount of the swearing that goes on whenever a blue shell is launched.

The other Nintendo franchises (outside of Super Mario Bros.) are less consistent when it comes to their accessibility. The Pokémon series has always had peaks and valleys in popularity, while Super Smash Bros. can scare people away with how technical it is. The Legend of Zelda series has always been more of a critical darling than a huge seller and most of the games in the series have been single player experiences, which means that your time in the land of Hyrule is limited, while a Mario Kart game can have infinite replayability.

When people think of Nintendo games, the first image that they will usually think of is Mario jumping from platform to platform, Link striking an enemy with his sword, or Pikachu emerging from a Poké Ball, yet the series that has truly captured the imagination of the gaming public is Mario Kart. There is something about the colorful stages and the small scale battles involving banana skins and shells that play out across the race track that makes the series so much fun, which is reflected in its amazing sales figures.

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