Ah, I didn't realize that the green line was the only tangible part, so now I have recreated a bridge and have completed the game! W00t! Awesome game ftw!
Well... I spent some time building my bridge, and they all just walked off of the cliff as though my bridge weren't even there. I think it's a good game, though. Maybe add several scenarios?
I got to 82 as well, but then all this weirdness started happening. It looks as though there is a "boss" there, but I did this wierd thing all over the screen so I couldn't see anything and died. Oh well.