Hmm... but the difficulty of getting 30 melons in each level of Yoshi's Story is a different sort of difficulty... one that springs from tedium and irritation.
It's like, you get 90% of the way through the level, and then something happens. Maybe you realize that there was a melon at the beginning that somehow got destroyed because you didn't find it quickly enough, or maybe you missed a race by a second and so only got 6 melons from it, or couldn't find all of the melons that appeared when you hit the ! switch, or other such events, which means - OH JOY! - it's time to restart the level!! The ENTIRE level? Yup, the ENTIRE level!! Many of their "secrets" spring from this kind of cruelty. Miss slightly, and you're forced to redo everything, because the "checkpoint" system is flawed at best, and the concept of lives... It's interesting, but the fact that you get scored for the number of lives remaining... And even if you didn't miss a melon in such a way that it can't be recovered, you'll usually end up sniffing around the level three times over before you get anything.
Nah. Yoshi or not, there were just too many things that weren't done very well in that game.
Go Moon!