Sorry to anyone not seeing text!
It seems like Chrome doesn't support the way I'm checking/updating the font size (my bad for not testing it in anything outside of Firefox before uploading). Until I fix that, unfortunately all I can suggest is playing on Firefox (you can try copying the "collatz-clockwork-save-state" from Chrome to Firefox if you want to keep your progress: https://developer.chrome.com/docs/devtools/storage/localstorage/
https://support.mozilla.org/en-US/kb/storage).
Thanks for playing, and sorry for the inconvenience!
edit: The text should at least be visible now, if not the perfect size.