The game might be unofficial, which we don't cover in this series.

First, have a look at the Tetris Fangames series and see if your game isn't represented there: https://www.speedrun.com/fantetris

If it is an official game that you're missing, leave a comment and we'll have a look.

Posting here because my request got denied and i was told to reach out to a series moderator (even though i don't think its entirely fair to classify sega tetris a member of the tetris series and more as its own game but i'm not gonna fight and die on that hill)

Sega Tetris for the dreamcast is missing

https://tetris.wiki/Sega_Tetris

here is my run:

I can't make a new forum, so I'm writing here. Please add a new tetris from SEGA https://dzen.ru/video/watch/6754494c16564623a0d1030d

Tried to get Welltris submited but I was told to get the Tetris mods to add it, i think it should be added it's a pretty interesting game

https://en.wikipedia.org/wiki/Welltris

Heres my 25 line run it's pretty bad I'm still figuring out the meta: