Coin-op Bop was an unknown level in Cuphead that got cut at some point prior to the game's release. While the level has an OST made for it, titled Coin-op Bop, and the code for the level appears somewhat finished, the concept was scrapped before the level's art assets were completed. Footage and unused art assets show that the level would have been in Inkwell Isle Two, alongside an unused NPC called Shelly.

The level code reveals that it would have been somewhat similar to a boss fight but would have changed the style of the level as the player progressed. All the phases are designed to resemble shoot-em-up games, where the player would have to fight off waves of enemies, clear the level of objects, or games where the player travels from one side of the screen to the other.