I really like the aesthetics! The music and sounds are subdued perfectly for the game's vibe. As someone who's sorta bad at tetris to begin with, I wouldn't mind fewer multiconnection blocks, but failing that, I just wonder if the original mechanics of tetris could be reincorporated to help somehow. Like if completing a row maybe caused the blocks in that row to close any down or sideways loose ends there (might not be possible, or way too difficult, I'd need to think that through a little more). Anyway, some food for thought.
Well done!!