I worry that I took "little to no plot" away from your request. This is not something I am into, so these suggestions are a little lackluster.
Anomalous Coffee Machine,
and its sequel 2,
and the latest installment 3: Type a word, drink the distillation of it's meaning.
Cabin By The Lake: I strongly enjoy this game. You chose branching story paths across several days, then repeat those days to try other variations. This opens new paths to build on.
You must be registered to see links
: Plot light base builder/tower defense.
Hard Stuck: rogue-like dungeon. This is more about the game play mechanics than any real plot.
HomeWork Master: Get in good with a girl, to try to get into said girl.
You must be registered to see links
: weird gameplay heavy, FPS style, horror themed, plot light game.
You must be registered to see links
: Get in good with a monster-girl, to try to get into said monster-girl.
PASEC: side scroller style shooter.
Quiet Girls: short RPG style game where you have to escape a spaceship.
Revenge of the Nerd: side scroller style fighter. Rape or be raped I guess.
: Enough story to understand why there are choices. Branching story about glory hole and a monster-girl
: Deck builder game with paperdoll style avatars that perform the actions on the cards.
Subway Tentacles: No plot, you control the tentacle monster on the roof of a subway car, grabbing passengers.
: FPS style fighter where MC gets raped by the opponents.
The Corrupting Train Feel-Up of a Strong-Willed Girl: No plot, grope a girl to escalating degrees.
: I couldn't get into this one. It's kinda like a trainer. Subject is a girl you kidnapped to turn (medusa like) into stone.
Tsuukin Densha, Tousatsu Sareru Shoujo (A Girl Being Secretly Filmed on a Commuter Train): No plot, grope a girl to escalating degrees.
Val Karee: side scroller platformer shooter.
: Weird game-show mechanic where MC is one of several people who may or may not fuck in series of meetings. There are win and loss metrics.
This one is separated for a reason:
Siren of the Dead: Strangely compelling game for being something I don't recommend. Each day advances the plot and introduces more zombie types. The game becomes a quest to fill the gallery with scenes that may or may not be interesting to you, no judgement. Warning. The scenes depict variations of zombies subduing and raping the MC, with increasingly significant body horror. Like biting off a nipple and fucking the breast through that wound while she is, or is not yet, dead, kinda stuff.