The special feature of this Tetris variant is the flowing movement of the parts. So far I have not seen a Tetris clone that does this... Only after programming I played the original Tetris. Options like the instant drop by space key or the preview I didn't include therefore not built in. The colors are very unusual. This is because I developed with a green monitor!
Thanks to Andreas Weidner for the "Guantanamera" music!
The actual program is written in assembler. Unfortunately the source code is no longer available.