Taking this to the extreme, [numeric] abused the user-defined characters to write a tiny game of Tetris that would run ... put his code for doing this online (ZIP file) as well.
Everything you need to run the AI is available for free, except the Tetris ROM. If you’re interested in how 8 bit games were built, this dissection is a great read.
N-Blox is similar to Tetris 1989. It does not use many of the new features such as the hold function and the four block preview. Players are also not allowed to change the keyboard controls ...