Sorry to hear it's not playable on your monitor. Hive Time was designed to be played at 1280x720 at around 92dpi. I can understand how that would be difficult on some 4k screens, etc..
A while back, I added an undocumented font_multiplier setting that will let you change the font size, though this will not change the scale of UI elements, and depending on how big you make text, it might overflow the area it's intended to be within and you may see unintended horizontal scrollbars. You can find this setting in the "interface" section of config.cfg.
You can find config.cfg either by clicking the "Open User Folder" button from the Settings menu in-game, or by looking in the folder listed in the "Log, save, and config file locations" section of the FAQ here on Hive Time's Itch page.
Hope that helps!