Welcome to the site @Cyldavor. First off, I would probably check out the user-maintained list of games. Alot of games on there that say “mini-game” or are by the same dev are probably going to be what you are looking for provided it states that there is weight gain. That list is not exclusive to the tag “mini-game” as it is maintained by users so there are lot of games on there that are probably short but of a different genre or descriptor. Also, the #gain-jam tag will lead you to a lot of short games in general as they are made for the yearly Gain Jam.
A few off the top of my head.
@Roops has a couple one being The Breakfast Chub
@lachevite has a few on the list provided as well as I think most of their games being shorter in nature here on their itch or patreon.
@sometimescozy has a few games made for the game jams personal favorites are Penelope’s Christmas and Culinary Combat.
W-oo-t’s Big Tiddy Goth GF Simulator.
Just to name a few.
There are plenty of games that are short, in different levels of completion and either free or paid so hopefully that helps a bit.
EDIT: Forgot to mention all my listed suggestions have visuals. I too prefer this.