Does the look of the DKC series match the gameplay?

[Zero Kirby]

What's odd is that Donkey Kong Country animated series was a huge hit in Japan. Also K. Rool is one of the most requested newcomers in Japanese polls. So I can't say DK is unpopular in Japan.

In fact I wouldn't say DK is unpopular anywhere. But what he lacks is a passionate fan base. Look at how much Mario and Sonic are discussed on the internet. Look at how much anticipation people have for each Zelda game. You don't see that for DK and I wonder why.

Donkey Kong games are hard. He also doesn't have quite as many as Mario, Sonic, or Zelda.

People expect a brand new Mario or Zelda game with every generation, on every system. Just as well, they're designed with the philosophy that each one is somebody's first - Mario and Zelda games tend to be easy to pick up and play from beginning to end. (With the occasional rare exception, such as Super Mario Galaxy 2 which was explicitly designed to be much more challenging.)

Donkey Kong isn't like that. On the surface, the controls and mechanics are just as simple as any other Mario game, but there's a lot of little nuances (air-roll-jumping and carefully timing button presses to get bounces... and knowing when not to) and the games start ramping up the difficulty pretty fast (Tropical Freeze is very notable in this regard - it kicks off the kid gloves five levels in, not even counting the super-challenging Temple levels).

Which I think is fine. Donkey Kong is the platformer for the experienced player looking for a challenge, compared to Mario which is there for anybody to pop in and have a good time. But of course, that means that Donkey Kong is going to have a smaller fan base since it's not appealing to as wide a demographic.