In a recent interview with Takashi Iizuka,it was revealed that Knuckles and Amy will appear in the DS version of Sonic Colours. The guest appearances will not affect gameplay but will help along with the plot. It is unknown if they will appear in the Wii version but since the DS was referred to specifically I doubt it.
Personally I don’t mind Knuckles as a rival but I hate Amy in whatever context. Even Sonic hates her guts. What about you? Do you hate her guts? Tell me in the comments.
[Source: Go Nintendo]