Hmm, ok, maybe something to try as a first step :
- after the piece is dropped, some machine cuts what sticks out of the container, and it is counted as waste score. If the piece is too big to fit the container, everything goes to waste
- then some machine fills the holes with some liquid, and it is counted as a unfilled score
(maybe you don't actually see any machine, and it's just abstracted for a score)
- player has a waste "life bar" and a unfilled "life bar", whenever one gets to zero, the game stops. Otherwise, you keep playing
- simplified variant : waste and unfilled are counted in the same score, only one life bar. But I think it's interesting to keep asymetry, it adds tension and a bit of tactics.