The init file is under /bin. In the last line of the first post in this thread, you can see where the renamed original init is called. Now, based on bonzi's message in this thread, I renamed init.orig back to init and just changed the /etc/profile file. This file is executed whenever a shell is started. I just added one line to /etc/profile:

/bin/player-tetris-loop &

And that file does just what it says. It loops back and fourth between tetris and the player all while I have a bash prompt on the serial port. I use the -s- option (don't use serial port) when I call player since I'm already using the serial port for my bash prompt. And I have the quit menu option enabled so I can get to tetris even if the unit is in the car.

Good idea, TheAmigo. I hadn't thought about "*0 lines" being misinterpreted.