Trapped in Time is a classic "Turn to page 20"-style CYOA work. You are a Chrononaut experimenting with a time machine. Things start to go wrong. The game invites many replays, being a 'replay'-style game where you just try to get it write.
The real innovation here is something that is beyond Twine's basic capabilities (although it could be implemented if someone worked hard at it). The game starts giving you mathematical formulas so that you can use a limited set of commands (something like, "To examine a room, add 50 to the first page that you enter the room in.") this makes the game both fun and challenging, because you can't easily reverse engineer the game, and you have to keep track of all the formulas.
The game includes a variety of bonus material and is fun. The story is not quite as exciting as most good Twine games, but the novelty of the presentation really made this game enjoyable for me.
Recommended due to fun factor.