I'm kinda confused ab the controls in this game. Looking at it, it looks like multiplayer is possible or a second preset? but using these controls doesn't work? Also, I don't exactly know how to use a controller even though it is clear that controller support is available. I also made a video about a weird thing with the shift key when in the pause menu:
Hiya! The game is only single-player, Pico-8 as a platform just shows the potential second player control scheme in the options for any game that uses the default pause menu. As for the color change from holding Shift while the game is paused, that's just another quirk of Pico-8.
Controls on controller are about what you'd expect: you can use d-pad or joystick to move, and the face buttons are mapped to Z/X. If you're playing a browser version instead of downloading it, some Pico-8 games won't properly recognize the d-pads of some controllers and you'll only be able to use joystick.