I have no idea why spamming crashed your browser tab. What specs do you have and when did it crash.
No clue why that would happen either. My specs are definitely just fine, and I'm running Firefox. Crashed on the "click" button when submitting name and score for the leaderboard. Don't have the error printout unfortunately.
Maybe its because I forgot to make the button click once. So it attempted to upload multiple scores at once. That's probably the issue.
