It's been a long time coming, but Cuphead is finally available. The highly anticipated platformer is notable for its beautiful, 1930s-era cartoon visuals and relentless difficulty, but hidden within the retro-style game is a secret mode that you may not be aware of.

Mild spoilers for Cuphead follow below. If you'd like to unlock the mode yourself, do not read any further.

In Cuphead's World 3 hub, you'll notice a turtle sitting by the docks. If you speak to him, the turtle will talk to you about pacifism, hinting that a special bonus awaits if you can clear the game's platforming levels without shooting any enemies.

If you do complete a level without shooting, you'll get a P as your grade. The flag you raise for the level will also be denoted with a P. If you manage to do this for all six of the game's platforming stages (Forest Follies, Treetop Trouble, Funfair Fever, Funhouse Frazzle, Perilous Piers, and Rugged Ridge), return to the turtle and he'll unlock a black-and-white mode and audio filters to give the game an even more vintage presentation.

Cuphead poses a steep challenge even without a self-imposed restriction like this, so you’ll need to plan the use of your Charms and Super weapons carefully if you want to unlock the black-and-white mode. It should also be noted that you only need to avoid shooting your weapon to earn a P grade; parries, dashing, and the Invincibility Super won't count against you. You'll also unlock Expert mode once you clear the game, which makes everything move faster than normal.

Black-and-white isn't the only kind of filter you can unlock in Cuphead. Also in World 3 is a monocle-wearing fork standing outside the shop. The fork mentions that he is looking for "Grade A" people, and it seems that if you can score an A or above in each of the game's bosses, he'll unlock a two-stripe filter, though you may still be able to unlock the filter with a few B grades scattered about your checklist. You can learn more about how to unlock these filters in the video above.

Cuphead is out now for Xbox One and PC. Despite its long delay, the game has earned widespread acclaim from critics. In GameSpot's Cuphead review, Peter Brown called it "a rare, unique game that truly stands out" and awarded it an 8/10.

This story has been updated.