Tetris source?

Question

JavaScript

Hello. I decided to write my own tetris (with blackjack and courtesans), but I just don't know how to do it on unity.
I have not seen normal examples, mostly bugged to such an extent that one 2 of them did not generate figures at all after the first one.
In general, we need an example of the implementation of Tetris on Unity3D without any walls (At least desirable), I know what it sounds like: give me Tetris, and I'll put textures on it, but it's not.
Well, or at least a lesson (preferably 3D Tetris, not 2D)

Answer 1

start in 2D, develop classes and structure, and then move on to 3D