Black & White and Vintage modes
This is a cool set of filters you can use to make the game look more "old timey". Head to the dock on Inkwell Isle and talk to the turtle sitting at the edge of the pier. He'll give you a hint about "seeing the game in gray", and what his riddle means is that you need get the "pacifist" rank by completing the following platforming levels without shooting an enemy (parries, dashing, and the invincibility super are still fair game).
The following are the six platforming levels you need pacifist status on are as follows:
- Forest Follies
- Treetop Trouble
- Funfair Fever
- Funhouse Fazzle
- Perilous Piers
- Rugged Ridge
Successfully complete this challenge and your flag will raise with a "P" on it, letting you know you've accomplished the feat. Raise that flag 6 total times, then return to the turtle and speak to him to get access to the modes, which you can enable in the pause menu. Black and White makes the game look more old school, and the Vintage mode changes the audio of the game.