they're not bad, they're just so damn mediocre
none of the levels are memorable, they're just a series of easy as shit segments grouped together
the game is super easy, aside from a few really hard parts that are only hard because they have some annoying gimmick associated with them - motion controls, comets etc.
and making you beat the game twice to see the real ending is an actual war crime
i can tell you 10 levels from both games from where im standing. maybe it's cos i grew up with it but it's made to be memorable.