As a pre-alpha, proof-of-concept, this has a ton of interesting potential. I hope you're able to keep developing it into a full game! The basic animations, especially those for the sex sequences, are quite good, the art style is a good blend of the inspirations you cite, and the limited sound effects you've implemented so far are promising.
Now, for some constructive criticism!
The basic idea of combat leading to either dom or sub sexual interactions is, while not original, a concept that I think has potential (although there's either got to be a much more varied range of enemies, or a lot more permutations on different positions - the ones you've got are all good, but they get repetitive fast).
I like the narrative sequence with the imp a lot more than the procedural interface you've got in place for all the other NPCs. Definitely think you should implement something similar for both victories and defeats elsewhere, as well as with the consenting humans inside town.
While it does seem appropriate for the succubus to have an attack that increases lust as much as it does direct damage, it seems kind of weird that they do it by throwing potion vials. Maybe once you've got some of that magic implemented, they could do it with a spell instead? And somewhat the same thing for the slimes - the visual effect should be just a glob of slime, not a thrown bottle. I noticed also that the minotaur and imp tails aren't animated while they're walking around - they stick out straight backwards (not sure if the succubus does too?). Presumably that's something you just haven't gotten to yet.
As some others have already mentioned, nighttime is definitely too dark to be playable without a light source. I saw someone's comment suggesting there's an equippable torch, but I didn't encounter such a thing - definitely would have used it if I'd found it. Maybe making a lantern that can hang from your belt, or a magic spell that creates a following light source? That, or night needs to be a lot brighter than it currently is. Even in town, the street lamps and the smith's forge create a pretty limited degree of useful light - they're visible from pretty far away, but don't illuminate the area around them especially well.
My last point is probably something you don't even need mentioned, but for the sake of completion: there needs to be a lot more weapons and armor. Particularly in the case of clothes, only 1 of the 2 bandit outfits feels suitable for a female character, since the other has no top at all (I don't exactly mind playing a lady that runs around topless, per se, but it feels weird in a setting where everyone else is wearing more clothes, even the succubi). I like the leather pants available from the smith, but there needs to be an optional bandeau top or something to go with it for characters with boobs.
Anyway, it's a great beginning! Keep up the good work!