Oh, with the rotation feel much much better! :D
And I am not sure, if that should be so, but the part of 'i' floats even when the dot is gone :) 
I implemented Super Rotation System so you can do T-Spin etc!
Yeah, about the i Tetromino I didn't get if it is better to drop the other part so it doesn't float, and at last I decide i is just put like that.