While devoid of fancy first-person graphics, and without detailed drawings of the trebuchet itself, the game accurately models the physics of the projectile, including its mass, the angle of launch, the force of gravity, wind and air resistance, and the counterweight's mass and height.
Fair warning to non-U.S. players, and to U.S. players who are engineers and therefore used to working in SI (metric) units: the game uses imperial (English) measurement units. It's still a lot of fun, however, and quite addictive.
Your friendly neighborhood SCAtoday.net Publisher (Justin) managed to get about 2475 as a top score after a couple of plays. Not so hot on the high score table, but I did rack up one near-perfect score on the "accuracy" part of the game.
Thanks to Lady Offria Pinkhand, of the Marche of Alderford in the Midrealm, for sending the URL to this extraordinarily-effective time waster.