I hear ya! I have trouble with small things on the Playdate too! I’m afraid the font is as large as I can make it without redrawing a new font, and I won’t have the time to do so any time soon. I tried to find a compromise between having enough text on screen to see context clues and a large enough font to be comfortable, but I understand it can be tricky.
As a workaround for now, could you perhaps play it on Mirror?