This TAS is of the 50 lines speedrun which is a category established on Speedrun.com. It is the main speedrun of this game together with 25 Lines.
This Run contains the same opening sequence as the highscore TAS until later levels the TAS perfectly uses the available longbars to clear down a stack of completed tetrises to reach 50 lines with as few pieces as possible.
The Mario segment stomps an extra goomba to manipulate RNG in tetris, this wastes 21 frames but the route used in Tetris is well worth it.
On the last piece i push it down fully to reach 50 lines faster. It is possible to not push down manually and let the game slowly drop the piece down for you. This saves the last few inputs in the movie but makes the TAS reach 50 lines slower and is therefore not done in my TAS.