I think you should have spawned the Tetris pieces from the start, not 20 seconds into the game That's probably why some people think Q and E don't work :D
Yeah, I can see that being helpful. Though given the flappy bird half, I guess it would have had to be somewhere where you don't immediately run into it but also see it?
The player could start off with a Tetris piece. Then they will be able to use Q and E straight away. After shooting the piece, they'll quickly learn to pick up the next pieces that come along