Old but gold is now starting to become an appropriate adage for "Cuphead," as the game reaches a commercial milestone of one million sold copies.

Studio MDHR, the developer of "Cuphead" took to Twitter to post a statement, thanking fans and supporters of the game since it has sold over one million copies since the time of its release.

"'Cuphead' has only been out for two weeks and we never could have dreamed of the reception we've received from our amazing fans! Today, we wanted to take a moment to thank each and every one of you for your support and we're excited to share that Cuphead has gone platinum with over 1 million units sold!," according to Chad and Jared Moldenhauer of Studio MDHR.

The developers were also proud to see that a lot of people are playing "Cuphead" despite its reputation for being a hard but fair game. The exact breakdown of the sales per platform was not specified, although PC Gamer assumed that the number was the sum between the PC and Xbox One. Steam Spy put the sales of "Cuphead" at 657,029 copies sold at the time of writing. The game actually ranked as the fourth best-selling game on Steam last week.

Critical success for the game also complemented its commercial success, as the game has a 96 positive review rating on Steam based on 11,379 reviews.

The revenue generated by "Cuphead" is now assumed to be $20 million since the game has a base price of $19.99 for both Xbox One and PC. "Cuphead's" success places its developers in the same league as the developers for games like "Super Meat Boy," "Stardew Valley," "Don't Starve," "Minecraft," and other successful indie game developers and their titles.

"Cuphead" is a run-and-gun 2D side-scrolling game where players control Cuphead as he attempts to collect souls for the Devil as payment for a gambling debt. A second player can also jump in using Mugman, Cuphead's cousin, similar to how Mario and Luigi help each other in their franchise.

"Cuphead" is out now and is available for Xbox One and PC.