Very nice, as a huge tetris enjoyer I've killed more time than I'd like to admit (like 20 minutes). It's just the simple original (the best) version of tetris and I think you've nailed the sound effects.
Only "bug" I found was that the theme music looped weirdly (got cut in some part and started from the beginning).
Overall I'd say you get exactly what you'd expect from a classic tetris. Good job, mate :D