I've been anticipating seeing this picture get colored, and now that I've seen it, I'm very impressed. The first thing that strikes my fancy is the colour, of course. You've done a magnificent job capturing the essence of a carnival. The shading is quite unique as well, especially on MK's hat and mask, although the banner could use a little more of it. The background is fitting, but I think it needs a little more flair than just black with a few dots for stars (like, maybe make the bottom the horizon, since MK's up in the air). I like the approach for the Ferris wheel where it looks like a silhouette in the background. As for the layout, I like how you have MK just up there watching everything while juggling some cards. It's a refreshing sort of look to the character!
If I were to nitpick, then I would say the balloons look like a different style of shading is used which is a tad bit distracting, and if you look closely, a little of the red balloon's color bleeds into the yellow's. It's also a bit unclear what Meta's sitting on (to me anyway..), and his feet could be a bit larger.
Overall, great picture, great concept, and Meta Knight looks sufficiently mysterious and badass even with the carnival outfit. ^-^
Just a note: this is my first formal critique, so I apologize if I'm a bit hard on you..