Well, it's time to open back up the IDE.
My friend Geoff brought something to my attention, which he's completely right about: In beginner mode, there's a bunch of dead-end passageways, with a yellow dot on the map implying there's something there. But there's nothing there.
Beginner mode, being a bit of an afterthought, doesn't have any of the slow-mo or checkpoint items. There's nothing to replace them, they're just gone. Which is weird and confusing.
I decided that an easy answer is to make them into simple collectible items. You find them, it says something like "you found collectible #3 of 16!" And maybe have an achievement if you collect them all. This makes the weird passageways make more sense, and adds a simple extra goal for beginner mode.
It should be pretty straightforward to add, we'll see how it goes.