It seems I can't play, no matter which option I choose at the title screen it always says "No save data found...", is this intended?
Are you interacting with the correct buttons?
The control scheme is GB studio standard, with "Z" on the keyboard being analogous to "A" on a gameboy, and pressing the keyboard "X" is analogous to the gameboy "B" button.
Pressing X in the menu while hovering over either text option will default to the false statement of no save data.
Otherwise, perhaps it may be a local cache issue in the browser.