Here is a theoretical question - one that doesn't afford an easy answer in any case, not even the trivial one.
In Conway's Game of Life, there exist constructs such as the metapixel which allow the Game of Life to simulate any other Game-of-Life rule system as well. In addition, it is known that the Game of Life is Turing-complete.
Your task is to build a cellular automaton using the rules of Conway's game of life that will allow for the playing of a game of Tetris.
Your program will receive input by manually changing the state of the automaton at a specific generation to represent an interrupt (e.g. moving a piece left or right, dropping it, rotating it, or randomly generating a new piece to place onto the grid), counting a specific number of generations as waiting time, and displaying the result somewhere on the automaton. The displayed result must visibly resemble an actual Tetris grid.
Your program will be scored on the following things, in order (with lower criteria acting as tiebreakers for higher criteria):
Bounding box size — the rectangular box with the smallest area that completely contains the given solution wins.
Smaller changes to input — the fewest cells (for the worst case in your automaton) that need to be manually adjusted for an interrupt wins.
Fastest execution — the fewest generations to advance one tick in the simulation wins.
Initial live cell count — smaller count wins.
First to post — earlier post wins.