CurlTi.me is a free online curling game that runs in a web browser, with a physics engine calibrated against published measurements rather than tuned by eye: a 19 kg granite stone, friction that rises as the stone slows, and sweeping that cuts that friction by about 6.6%. Play a friend over a shared link, or a computer opponent that searches the shot space instead of following a playbook. No account, no advertising, nothing sold.
The written pages need no JavaScript at all, and explain the game in full: