Why? Cause I don't think it's ever been made in DB yet.
I put it in snippets instead of showcase, because it's not quite showcase material yet. It's fully playable, all 7 blocks rotating, row completion, scoring. Only there are no levels, and if you reach the top of the board, it'll probably crash cause there's no code to check for that yet. Media included, enjoy!

http://www.dannywartnaby.co.uk/rgt/attachments/tetris.zip