Nice game! Liked the movement, loved the music, sound effects were all satisfying! [Now nitpicking on smaller things since the game is pretty good] It seemed a little generic as far as the theme goes, but 🤷. Would have liked a checkpoint system, even if it was just at the last coin collection so I didn't need to start all over when caught; this is as simple as instead of resetting the level after the caught timer, you just move the character to the last coin position, which you could set on coin collection.
Small bug I'm guessing you're aware of: I can recollect skulls if I die so I could have as many skulls as I want haha. Not super trivial to implement as you'd have to keep track of which skulls were collected rather than just how many, and then destroy the skull on level restart if it was already collected. Not that much more difficult though than your persistent skull counter.
Nice quality game, thanks!