I love tetris attack, I played both versions since it was re-skinned with Yoshi when released nationally. Good luck, I plan to make my own normal Tetris on here soon. It may be advance but I suggest using a number list that is turned into a 2D list with expression math that lets you check and change each index.
I have explained it here:
I Tried making a 2-dimensional list - #4 by JR01.