While fairly simple at its core, Cuphead has a few little secrets. Some of these hide in plain sight, whereas others are purposefully hidden and will technically never be seen. Finding shortcuts to other levels in each Overworld isn't usually too tough, but did you know there are hidden coins on those screens, too?
Not only do you need these coins to unlock achievements and trophies, but they're also needed to buy out Porkrind's Emporium of all those juicy perks and weapons. You'd think risking life and limb in the Run N' Gun stages would be enough here, but then you'd be wrong.
YouTube user Perfect Score quickly outlines where to find the hidden Overworld coins in a video that comes in at less than a minute long. After all, each zone of Inkwell Isle is kind enough to only hide one coin each, so it doesn't take long to pick up what you've missed.
Essentially boiling down to sliding Cuphead's cuphead against walls, these coins are typically hidden behind setpieces; meaning you're just slamming the Confirm button until you happen across one. The video will show in more detail where to find them if you're not looking to go on the hunt, so don't worry about wasting too much time.
But, as usual, most of the game's 40 coins come from the Run N' Gun platform sections. These aren't usually too hard to grab, but surviving with all 3 is another story. Grabbing 4 through these sections should give you enough for that essential upgrade you think you need.