A less-than-half implemented Tetris-clone in QBasic
It is a Tetris clone in QBasic, a language from the 80's that you'll need MS-DOS on an older system (Think 386-Pentium range). You can also run this with wonderful DosBox.
I've been compiling it with BC7, but 4.5 should work just fine as well.
This is a little bit of childhood revival for me, used to write in this language a long time ago and wanted to dabble in it for fun.