One player builds a block tower in the center of the board, then the other players attempt to destroy the stack using either a ramp, catapult, or pendulum. The destruction method each player uses is determined by a die roll. Points are awarded to players (including tower builder) based on how successful/unsuccessful the destruction attempts are. Tower building duties rotate among players. First player to reach the end of the scoring track wins.
I obtained a not so good photo copy of the instructions & have retyped them, as well as adding a few images. There is a note re: the catapult as even the official instructions had a misprint (well, it actually didn't print the line at all), so I added a "tip" accordingly. I used the b/w images from the official instructions, stock photos from the web & then the info about Uncle Skunk Toys from the official instructions.
I put together some unofficial rules that does have the scoring system. This document is based on comments from a few forums, including Boardgamegeeks.
There is also a small video demo of the game from Uncommon Games on YouTube: http://www.youtube.com/watch?v=YmrS1O17d9E