Microsoft today announced Cuphead: The Delicious Last Course - DLC - at its E3 2018 press briefing. Cuphead and Mugman make a comeback for the DLC, but there's also a new playable character; the Legendary Chalice is joining the adventures of the duo as Ms. Chalice.
The new DLC will also feature a new isle, new bosses, weapons, charms, and more. Neowin's review of Cuphead gave it an 8.5/10, so hopefully the DLC will stand up to what the original game offered.
In its description, StudioMDHR states that this is "Cuphead's final challenging quest," which could perhaps mean that this is the first and only DLC that the game will get. At the moment, the game is discounted to $16.99 on the Microsoft Store.