I didn't like the opening of Runaway either, for the reasons mentioned (why the flash forwards?
). However, although I don't like anything remotely spoiler-ish, it is not that it says a lot. It just goes too quick for that. So, unless you pay a lot of attention to it and watch the intro again and again, you have nothing to fear about the game being spoiled.
On the other hand, better to have something to look at than just Brian in a black background narrating...
I'd say, give the game a try. It gets better after the weird opening sequence. It is not as good a game as Broken Sword, and when playing you should definately try to refrain from make such a comparison. Runaway is worse, don't expect too much, but all in all it's a nice little game to play, so if you have some spare time, give it one more try