If you navigate your browser to here, you will find a most amazing thing: Tetris crafted out of a SED script with a bash wrapper. The page is in Russian, but Google or another translation site will tell you that the first few words read:
Wrote a small Tetris on sed’e: sedtris.sed and wrapper on Bashe sedtris.sh
Download both scripts to the same directory, on the command line do:
bash sedtris.sh
It’s actually very good!