Not sure that I've seen many educational adult games, so this was kind of neat!
I do think some of the menu buttons (Like skip, next, etc) were a bit small and easy to miss. Also bringing up the menu via right click is handy, but it interrupts the flow of things if you accidentally click it. Otherwise, the only thing I would personally changes is some of the names of the main gameplay options. "Take a crash course" feels like it should have been the 'Study' option, where you learn the information to start out. And I think the option of being asked questions for score could be labeled 'Pop Quiz' or something to let players know that's where they're being 'graded.'
Overall though, very unique concept and well done!