I dunno, it's pretty replayable. In the same way that I enjoy loading up Sonic the Hedgehog 2 or Super Mario World, simply PLAYING Limbo feels great. I don't believe it will match those games in that regard, but it's definitely the kind of thing I could find myself picking up and playing on a whim. It's definitely replayable in the same way that a 16-bit platformer might be.
It's so much better than Braid in that regard. I enjoyed Braid, but one time through was more than enough and then I was done. It felt tedious to replay. Not so with Limbo. The fantastic controls, atmosphere, and design encourage skilled play. There is a lot of timing that comes into play here without feeling frustrating. This is NOT like Another World or Flashback in that regard.
There really aren't any filler segments either. The game is awesome from start to finish.
I cannot believe how good this game actually is. The visuals drew me in, but the experience and feeling of playing it keep me going. This is one of the most inspired games I've played this year. Absolutely wonderful.
It's like a retro platformer meets ICO meets an old school European PC/Amiga game.