Tetris 2008 is a official free Flash game released in Japan.
This game is B-Type. Each stage's goal is to clear 25 or more lines.
Beating a stage will reset the playfield, and increase height (the amount of garbages) by one. If you beat height 5, the level increases by one.
Unfortunately, there are many bad points in this game. First, there is no online scoreboard. Second, the game hides your score if you die. Third, DAS is very slow. Finally, you can't change keyboard mappings!