There are lots of time traveling shows out there. When I speak to folks about time travel they usual bring up Doctor Who & then go on about it at length. I stop them dead when I mention Mirror Mirror which ran in 1995. It was an Australian & New Zealand kid's show but it was a very smart & funny kids show.
The show didn't talk down to kids at all & still to this day has a huge fan base. The plot ran something like this :The main character is given an antique mirror and the image she sees is that of a girl from the early 1900s.Things don't go as planned when the two 14 year old girls discover they can see through identical mirrors 100 years apart and that they can travel to each other’s times. At first this is a source of wonder and delight but the two girls, Jo and Louisa, quickly discover they must solve an enormous problem.
The show makes very clever use of the its time traveling motif while at the same time never talking down to its young audience.
The plot is very involved & you can find out more about it Here Bewared there are some major spoilers in the wiki entry!
Mirror Mirror & The OSR
There's quite a bit already that's been done with time travel with Old School Heretic's blog Here . The idea of an artifact either technological or magical as the focus of a campaign is one that seldom gets bandied about. In Mirror Mirror the time travel motif isn't simply a plot device but the central wheel of the story. The same idea can be applied to a Human Space Empire game given the game's extensive timeline.
The idea of going backwards & forwards in time to either the past of Empire of Petal Throne or towards its future could have grave repercussions for both campaign worlds or not unlike the Time Tunnel have very little influence.
The central idea of the show was their engaging characters against a huge rolling blanket of history. The idea of these engaging Npcs & their stories is what propels Mirror Mirror and even the Time Tunnel.
We want to know what happens to them. As players we want to find out. The device is merely the instrument to get the adventure going.
I often find that time travel shouldn't be over used in table top role playing. Time Master & even the Doctor Who rpg can get old very quickly but slipping in the occasional Star Trek style time adventure will engage your players.
History can work for you or against you. Role players are often history buffs & can prove to be a pain in the rear when it comes to knowing every detail of historic events. This is why a game like Empire of the Petal Throne is perfect. It allows you to fill in the gaps as you will or create alternative histories that can confound even the most strict Empire fan.
Knowing an object's position in time & space can give your adventures an anchor that might be used again & again in a campaign. Use the technique sparing though it can get on players nerves & make them feel really helpless.
Keep notes rather then scripting adventures when it comes to time traveling adventures.. It helps to be flexible as a Dungeon Master. These are just some random thoughts about thinking outside the Tardis when it comes to time travel. Excuse me while I step through this antique mirror!