Game designer Eitan Glinert (Slam Bolt Scrappers) told me over dinner last week that he's really good at Mario Kart games, good enough that, a year ago believed he and his colleagues at Fire Hose Games could gold-medal all the races in all the console Mario Karts for charity in a 36-hour stretch.
Unfortunately, Glinert and friends failed to get their gold medals for charity. They choked, I guess. But Glinert did get a blog post out of it, which gives us these rankings, from toughest to easiest, and a theory.
The Super Nintendo'sSuper Mario Kart (toughest)
The GameCube's Mario Kart: Double Dash (2nd toughest)
The Nintendo 64's Mario Kart 64 (2nd easiest)
The Wii's Mario Kart Wii (easiest)
Not too shocking a list. And his theory about why this was?
The original Super Mario Kart was likely so brutally difficult due to an inability to program especially smart AIs [artificially intelligent opponents] . Rather than spending lots of time trying to (most likely unsuccessfully) make smart AIs the programmers simply opted to create a set of advantages for computer players that just feel flat out unfair. Perhaps this helps to explain why the N64 version was easier, as maybe the developers wanted to create a more accessible sequel that would be less frustrating. With the advent of the Gamecube, a system designed to speak more to "hardcore" gamers, it seems that Nintendo made their greatest effort to create a truly balanced Mario Kart that would appeal to and work for a broader slice of audiences. Of course, with the Wii's focus on a more casual audience it made sense to tone down the competitive nature of the game to make it easier for less frequent gamers to pick up and play (and play well).
I'll leave it to you readers to assess where the portable Mario Karts fit in on the difficulty scale and to debate how tough the 3DS' Mario Kart, slated for release by year's end, will be.
On the Relative Difficulty of Super Mario Kart Titles [Slam Bolt Scrappers blog]