Pretty good Tetris Attack, @kuritaro. The speed is a little fast I think for a beginning level. Maybe have EASY, MEDIUM, HARD.

Possibly have levels where bad blocks fall (black) that are cleared only if they touch a block being removed. There are many possibilities. I would refer you to what I believe is the first of this game:

https://youtu.be/W-kXJa_5R4Y

Thanks for playing @dw817.
I used to play this Yoshi game when I was a kid.

I tried to make it a quick game, but you are right, the increase in speed is too fast for those who want to play slowly.

I will now implement the difficulty level selection.