Yes, that's exactly what I meant. Getting ONLY the green melons on each stage has always been the goal to get 100%. I remember vividly filling up the records screen and even sending a results photo in the post to N64 Magazine back in 1998.

I'll try and dig up the issue that confirms the goal is to get the green melons. It's hard mode yes, but it's not exactly a hidden goal. Yoshi's Story is very intentionally vague on providing any instructions or written goals to the player, but the instruction manual and guides do.

Edit: here we go. Instruction manual scan, page 18. Specifically tells you to collect all melons for the best score. It was always there and the game guides of the day made it very, very clear. https://www.gamesdatabase.org/Media/SYSTEM/Nintendo_N64/Manual/formated/Yoshi-s_Story_-1998-_Nintendo.pdf

Edit edit: this is a sore point for me as there are a lot of traumatic memories being bought back now of getting to 29 melons then accidentally eating a banana and having to start over! Was a fucking pain in the arse and I remember spending hours and hours on it.

Yes, that's exactly what I meant. Getting ONLY the green melons on each stage has always been the goal to get 100%. I remember vividly filling up the records screen and even posting a results photo to N64 Magazine.