World of Goo: nonsense story

There's a story, yes.  No idea what it's meant to be about.  There are balls of goo which stick together and you can make structures with them.  Then other balls of goo will travel along the structures and you can then use them to make more structures.  And then the structure will fall over and the mouse doesn't move quite quickly enough for you to rescue it.

I've finished the first world, but that last point is just a little too irritating to continue.  I can't find an easy way of fixing it, either.