The variety in its environments is quite high, and the large number of mission objectives will certainly challenge you for countless hours. However, the overall level of difficulty isn't that high. [Nov 2002, p.46]
And play through you will as the repetitive nature of the game offers very little challenge despite the inclusion of boss battles, secret areas and herding puzzles. At one point you will have to guide a giant lobster into a cave and seal it with falling stalactites.