how about "steel"  gooballs, that can make very strong bonds,
the tradeoff is that they would be very heavy, and able to tear down a structure that isn't well supported enough.

another type could be "mercury" gooballs, that cant be used for building an have to get to the exit (like beauty balls) though because they are very heavy, different tactics would be required.

There's about 50 threads like this now... Search ftw...

Some really interesting stuff would be possible, if only kyle or ron would come on and tell me the parameters for the 'rigid' strand type. Cos I'm damned if I can get it to work properly.