The demo (or, more accurately, prequel) to Love Life, REM Cycle, is still (rather appropriately) in development hell, but I still want to take this post to explain what exactly I mean by "horror dating sim."
First, what it isn't. Sure, there's an amount of "dating is scary because anxiety" and/or "fear of commitment/rejection" that might get explored through certain characters come the full release, but it isn't the focus of the game. The "horror" part and the "dating sim" part exist as two sides of a coin - part of the same whole, but not exactly intermingled. This is best explained as a day/night cycle.
During the day, you do daytime things. The setting is an all-girl cram school (if you're not familiar, think technical college with a dress code; post secondary education that still isn't quite a university), so these daytime things include attending class, befriending and/or flirting with the various love interests, and... Let's call it "managing your libido." I haven't quite decided on an exact day/night cycle yet because REM Cycle uses a different system, but right now, expect a typical morning/day/evening/night layout. In fewer words, the game in daytime is a dating sim with RPG elements.
At night, the world changes. The halls and classrooms become twisted reflections of their daytime counterparts, classmates are replaced by nightmares, and horrible abominations (that look eerily like your potential partners) roam the halls. You might need to find a key, fight for your life, run for somewhere safe, or face your fears and complete a specific goal in order to progress. To summarize, the game at night becomes a survival horror RPG.
The game's theme of duality still applies here, so there will still be things to do on either side in order to progress on the opposite side. For example, a love interest may refuse your advances until you do something about their night-time counterpart, and getting to know that love interest better as a friend might make that task easier by weakening the nightmare. Or it might make it worse, and doing something about the monster haunting you will cause their daytime counterpart close themselves off to you. Which applies to which will depend on the character, and will help each love interest feel unique, rather than having a couple dozen instances of the same relationship that requires the same grind over and over.
I also intend the game to have no "game over." Certain relationships may have a hard fail state (though this will be rare if it is included), and there will certainly be consequences and "soft" fail states, but you will never actually die. "Losing" during the day will penalize you somewhat, but there's nothing particularly deadly to encounter. The night, while full of potential death, is also a dream; dying there simply means halting your progress and waking up in a cold sweat.
Doing things this way (especially in RPG Maker) presents some interesting development challenges, which I think will make for some interesting gameplay once it gets to the full release. As far as REM Cycle goes, the main loop will focus on only two potential love interests and will have a more linear story, but will open up to the final intended sandbox style of dating sim by the end so you can experience things first hand (and will hopefully let you bring your REM Cycle save forward, too!).