After further whiteboarding, I’ve decided my “Tetris variant” game is in fact identical to Tetris, but (a) upside-down, and (b) not fun. The “interesting shape” game rule that I envisioned is really just creating fully-filled lines of blocks, and that’s Tetris. Splitting the line-creation task out into a separate part of the game field doesn’t improve the play of the game, and re-combining it with the rest of the field is… Tetris.

So back to the drawing board. But at least I’ve written my pygame skeleton, which I had to do sooner or later.