Buttons and console names for retro tracks are in the High Private Use Surrogates (starting from U+DB80). More "squished" characters (used for Bowser's Castle 2 in french and maybe other circuits because normal characters don't fit in the menu) are in the Halfwidth and Fullwidth blocks.
Recreation of the 6px pixel font used in Nintendo's "Super Mario Kart" (1992) on the SNES. In the game, the font has a 2px spacing to account for the outline. In this recreation, I opted to just go for a 1px spacing - if you do use it outlined, make sure to add the extra pixel for authenticity.
Update Sept. 2019: added ":" and "," and fixed incorrect "Q", "V", "(" and ")"