Shouldn't there be a 100% version of every category, where you collect every single coin (both red and blue) in each level?

Would be a considerable category, but it must be known that not every level in the campaign has a coin (if I'm remembering it correctly) and is completely impossible in the case of Water Levels by Gkabyssflorida

In that case, the rules could change for each level, in regards to whether every coin is obtainable or not.