Thanks for playing!
One of my alpha testers wanted fewer sharks, too! :O Might try making less sharks, the lower the rate of the player's score increase, to auto adjust difficulty.
Originally, I didn't intend it to work on the browser, but then I realized that I had to either export it to Windows, Mac, and Linux, or export it to the web. And as I don't own a Mac, I wasn't able to export to Mac. So I had to go with the latter option.