The thing was, I loved the animated film of the Flashpoint Paradox which I have just been slagging off. Despite my problems with the main plot, it was great to see very different versions of well-known characters in dystopian situations. I was well into the stakes at the end, and breathed a sigh of relief when it was all stopped from happening at all.
Which is kind of the whole point. Time travel, unless you have something genuinely original to do with it, is just a tool. It is a plot device to make conflict, character, and colour happen in your sci-fi.
Put the drama first. Time travel is the means, not the end. Any resolution using time travel has to be involved with the human factor (eg Looper; the end is rooted in character development, and time paradox is just what he uses to make it happen).
It’s like a laser gun. Simply having a story that says “wow, this guy uses a laser gun!” is going to need more to actually make it worthwhile, maybe even if you are the first person ever to write about one. Maybe the story focuses on trying on to build the gun in time to stop the monster, or on the implications of its invention. Maybe someone is resisting using the weapon, but finally bends and shoots the monster in the last act. Perhaps there were hints of mystery about a character, and them suddenly producing a laser is a big reveal that invites further questions. But the laser itself is not the only point of interest.
A story needing interest beyond the gadgets is hardly a revelation; but time travel is such a McGuffin that it offers some specific pitfalls.
Thanks to: Terry, Sandy, John, and the rest of the writing group