Dunno if it's a good thing or a bad thing but if you don't get it exactly right you cannot finish. It annoyed me for ages on one, I had it hitting the goal board forever (if I didn't stop it) from one of those catapult things. Got a few clues and the end object? A catapult thing....grrrrrr
and you have to have ALL the bits out to complete it - but if you can get all the bits out and manage to still win - it, 10 bits, but you can get to the goal board with two catapults - it still counts as a win.
and you can get hints at the cost of 100 points of the level score.