[throwaway27448]

> the lines have to clear.

Sorry, the lines have to clear what? Surely there must be some kind of constraint on "lines" that they have to overcome.

[edoceo]

The lines (rows) in Tetris have to become complete and then disappear to make room for the new falling pieces.

In code the thing has to become stable, can't just keep packing more and more noise onto it.

[tekacs]

Absolutely this: and it needs to ideally become the kind of set of abstractions that mean that every new thing added uses less net-new surface area than it would without them.

[tekacs]

I mean that at the bottom of the Tetris board, the lines need to vanish so that the Tetris board keeps moving downward and doesn't grow unbounded.