Thanks for all the comments.
Haha well not all gimmicks need to be immediately found . With smart level design you'll pass the same areas multiple times throughout the game. The coins will also return to their place after a while.

And keep in mind the youtube is horrible quality. Will upload a screenshot later.


EDIT (click image for bigger size):


Yeah it's still quite tiny, but those coins aren't really relevant. You'll just have to search well for them. Part of the game .