Tetris was a complete game. Probably the biggest technology feat in Tetris was the sound engine. I'm rather proud of it, considering that it was brainstormed in a bowling alley. The Song Player is basically my sound engine broken out as a separate program. I did this so I could play around more easily with the sound format, and also so I could explore 6-voice sound some as well.
Pong is actually embarassing, coding-wise.
You recently won first place in Mike Hayes' Intellivision Library 1999 Intellivision Summer Development Competition with your Tetris entry. The family is proud of me. So, I decided to try it out. She TAs a geology lab, and it was rather tedious to send out grades manually. So, now she exports her spreadsheet as a DIF file, and my program does the rest.