WOW!
This is a very cool version of Tetris! It's really hard, but then how could 3D Tetris NOT be hard? I could only get a few hundred points.
The graphics and style are superb. The animation is smooth and the movement is easy to understand and use. Of course, some sound would be good, but I am not holding that against your score.
I assume you actually scripted a 3D engine for the game, and I am amazed byt it. I'm also amazed it fits into 19Kb. Sweet.
There does appear to be a bug at the end of the game. Once you finally lose, the game proceeds to the main menu screen where you can choose a level to start at. However your score is not saved to the high score list and the the control instructions are not shown.
Still, it's cool. I hope you submit more work in the future.