Super early release, so take this review with a grain of salt.
As of the time I'm writing this, the dev's being vague here and the Itch page is useless, but basically it's just Tetris and the woman's belly gets bigger every time you clear a line.
The Tetris part of the game is pretty barebones, but it works (no, I don't know if it supports T spins, haha.) It feels like the line block has artificially been made less common though, since after clearing about 90 lines, I think I've only seen the line block itself show up maybe five times total?
As for the character, all she does right now is T-pose as her belly grows, and she gets huge.

Is it worth playing right now? Sure, if you like Tetris at all. Dunno if I'd entirely recommend it (yet) if you DON'T like Tetris, but that's a different issue, I suppose.