I used to play this at my friend's house. Our fun came from two basic activities. First, we enjoyed taking turns looking things up in the encyclopedia. Second and perhaps more importantly, we LARPed the hell out of the time machine. Every time we followed the clues to a new time, we'd do a countdown, make up technobabble, and throw ourselves out of our chairs like actors on Star Trek. No game is more than a stage for its players' imaginations.