The Patriot Spy - Webrangers NPS
This cool interactive from the National Park Service starts right: it has sound!. Designed to introduce students to four of Boston's historic locations, it assigns students four tasks involving a painting or document. (I masterfully got all 4). Completion here grants you a token to the larger Webranger game, and also links to the individual historic sites.
IMHO, the play to "critical thinking skills" is a little heavy; and I'd shorten the introductory directions. Also we learn almost nothing of the people involved. Still, kudos to the Park Service team for this exploration of learning through sound, motion and interactity.