I'm No Sub! Sex Game Download

Reyas was a prince. Then he was stupid. A deal with the succubus Nay flipped his life upside down and left him an incubus in his own kingdom, with one rule: power comes from service, which means focus on other people's pleasure or lose your own, and hunt Nay down to undo the contract.

The Deal That Ruined a Prince

Reyas starts the game with the title of prince and none of the advantages. The decision to make a deal with the succubus Nay is the event that ends his life as a prince and begins his life as something else entirely, and the game does not let you pretend the choice was a reasonable one.
The cost of that deal is not a one-time payment. Nay converts him into an incubus and leaves him to figure out what that means inside the kingdom he used to rule, with a population that does not necessarily know or care who he was before.
The single objective that organises the whole run is simple: find Nay and make her undo the contract. Everything else in the game is what stands between you and that conversation, and the kingdom is where you pay for every step you take toward it.

Power Means Service, and Service Means Her Pleasure First

The core mechanic is the one that defines the entire game. As an incubus, Reyas gains power by harvesting lust energy, and lust energy only flows from the pleasure of the people he encounters, not from his own.
That rule creates a hard constraint you cannot ignore. Cumming drains your own energy, so the failure state is not losing a fight but losing yourself at the moment a fight should end. Every encounter is a discipline problem first and an action scene second.
The inversion is the interesting part. Most adult games treat the male protagonist's pleasure as the score, and this one explicitly treats it as the cost. The player who focuses on what the other person is feeling will build power faster than the player who chases a quick finish, and the game is structured around that lesson.

Seduction as a Kingdom-Wide Progression Loop

Because Nay is somewhere in the kingdom and not in the first room, Reyas has to seduce his way across it. Each encounter is both a power source and a step in the geography, so the map you open up is the same map your energy bar is building on.
The kingdom is not a neutral stage either. Reyas is a prince who is no longer a prince, so some of the people he meets already have opinions about him, and some of them have leverage. Seduction in this world is partly court politics and partly the mechanics on top of it.
The tag set on the itch.io page tags the build as Fantasy and Monster Girls, so expect the encounters to be distributed across that roster rather than across a single romance line. The game reads as an incubus tour through a kingdom that already existed before you arrived.