This list focuses on horror games and monster H scene based games. More game mechanics and hardcore H scenes, and less tentacles.
Notes:
1) This type of sub-genre is huge. I probably won't touch or play all the games/visual novels out there, just the ones that appear to stand out. Also I can only read English so I probably won't cover rpg type H games.
2) Games that show an older add date do get revisions over time. What text you see today may be different in the future!
3) Please support the devs. We want them to finish their games. We want them to make new games with this kind of content.
A space action platformer - puzzle platformer. Unfortunately the developer no longer has the coding for it. It is compete but not a fun game to play as a platformer.
The MC romances and bangs animorphic ladies. (More furry than monster maybe.) It has fairly interesting writing, great illustrations, and so forth. Plays as a visual novel and fetch quest for romance.
Allow your ladies to get converted into sex craved and obedient monsters by banging monsters. It has an interesting strategy game in there with tiles. Also on steam.
The main lady is a mix devil-angel. Plays like Baldur's Gate 3 dialog checks, stat building for romance over a visual novel. It is pretty entertaining with good writing.
Fantasy visual novel, fairly straightforward, no animation just will crafted still illustrations
This is one is pretty good and keeps getting better with every build. Still under dev. Highly recommend trying. The MC fights her way through fantasy settings, monsters, men, etc. Lots of player choice in this one. Great high fidelity models and scenes.
MC has to survive a bio-medical facility with monsters trying to impregnate her. Could use some polish but alright.
From the makers of Drain Mansion, still in dev. It has a similar feel but a bit different of being chased / reverse rape vibe. Great game design and monster girl H scene content.
The game that got me on the H game bandwagon. Monster girls / succubus themes, all the pixel art, hidden content and gameplay that is great. Another one that you like to lose a few times to the ladies, until you keep dying. Reverse rape genre. Also on steam.
Monster girl / succubus NSFW, reverse rape. Also a d-list game so stuff may be blurred. I played an early build and enjoyed it as a fun game with some great design. A game you lose on purpose until you keep "dying", lol, if you know what I mean.