@leahsdad, I had not really considered that as being part of the difficulty problem before, but I do think there is such a thing as having foregrounds and backgrounds too detailed and busy that it disrupts your ability to 'read the terrain,' so to speak. Actually, the layers in this game are not too busy, but what compounds the problem is the fact how critical it is to know every little slope. The end result of your race is very sensitive to the smallest movements.
Something else I've been thinking about is whether using the d-pad to tilt your buggy is a hindrance since often you want to make a precise tilt, quickly, to reach a certain angle, and a digital input simply isn't responsive or accurate enough. Analog control could have made the game easier to play, perhaps.
Yes, I can see this game being very enjoyable to play on the 3DS!
(And is it just me, or does anyone else wish the story levels were numbered or at least grouped somehow! Instead you just have to scroll through a long list of names. If I hadn't looked it up online, I wouldn't have known how many levels I had cleared through!)