I hope you don't mind if this is a bit long-winded as a comment.
First, I want to say wow. This game's production values are quite high! I think my eyes were wide open during the entire play session to say the least!
The overall concept of the game is interesting. Adventurers go on adventures where lewd stuff can happen. With a title like Jessika's curse I can see that there's going to be some kind of overarching narrative though. I wish you luck on the game as a whole!
Now about the gameplay experience as a whole.
First the hub world:
It looks beautiful, and the NPCs are brimming with personality.
When I was thrown into the hub city and the message said to explore, I thought I would be clicking on buildings since that's where an ! point was. Turns out you can only navigate the town using the icons at the bottom left. I don't think that's very intuitive. I think if an area has a quest, instead of showing the marker via the in-world location it should be shown via the icon, OR you should be allowed to navigate the town by clicking on the buildings.
You can't tell what the skills are in the skill upgrade menu. You only see icons but not what they actually do. Maybe hovering over the icons should give you more details?
You cannot re-enter the forest after defeating the boss. Don't know if that's a bug or intentional though.
I'm also not a fan of the lack of sound effects when interacting with buttons and the like. This part shouldn't be too hard but I hope you guys don't neglect it.
Oh also the Church doesn't have a current location tag.
Regarding the menus themselves,
I don't think the designs are very future proof. I haven't seen a scrolling menu at all. So will there only be 8 levels to increase your weapon by? Is it just a weapon and armor for equipment? What happens if a user has 20 skills?
Also when I was trying to level up to 4 while I had 200g and the cost was 200g I couldn't do it. Is the cost calculation g > cost or g >= cost?
When it comes to exploration I have a few things to say as well.
Currently, all movement is designed with moving "right" in mind. When they stop they stop facing right. The camera is always facing right as well, but there seems to be times when the game wants you to move left.
The times you move left, I was feeling that the camera being so right-centered was wasting screen space with information I didn't want.
The parallax on the last layer is also incorrect. The last layer of parallax should always be centered on the camera. From a programming perspective it moves the most, but from a visual perspective it shouldn't move AT ALL. Always where the background is. Your first and second layer parallax is perfect though.
Before I get into combat, I'd also like to mention the battle transition. I think it's interesting that you guys are aiming to have the battles happen right there on the field. If that's the case though I think the enemies shouldn't just appear as they do now. Maybe jump out of the background or at least fade in.
Also, the treasure chests stay on the minimap after you open them? I understand the enemy icons staying if the combat is recurring, but the chests don't make much sense to me.
Now Regarding Combat:
It's very straightforward and simple. I'm actually not a fan of super simple combat systems but complexity usually comes with time and this is just a demo so I don't mind. There are a few errors/bugs I'd like to address but I'll save those for last. First a general flow conversation. Right now the flow is to click on the enemy, then click on the skill to use. I think maybe the reverse would work for a faster battle flow. Especially if you can choose which skill to use with the numbers. So press 1,2,3, or 4 then click on the target. Some skills don't even need targets so choosing a target first is moot right.
I'm also not sure I like if I can't tell the numerical value of how much damage I'm taking. Usually if you show damage numbers, you'll show the actual HP in number format somewhere so you can better strategize. I don't think the current display is very helpful when it comes to planning strategies.
Also regarding the turn order, I don't think you need to show turns of people who have already gone. If the active turn window is scrolling left, then I think the active position should be the far left. There's no value in knowing who has already gone.
Overall the combat is fine otherwise... I'll mention my personal suggestions later, but I'll now be talking about the bugs I found.
During relatively long battles, turn order got a bit messed up. Sometimes two enemies acted at the same time, even though I never saw that before. I appreciated it since it made enemy turns go by a bit faster, but I feel like it might've caused some errors at well. At some point it became my turn before the enemy even finished returning to their starting positions.
Not only that but enemy positioning on the map didn't look good at times.
The enemy on the far right is on top of the building?
Mouse is on top of the rocks? Visually it doesn't look good in my opinion.
The camera also overextended at times and just made everything look aweful (on the left and right side of course.) A simple clamp should fix this when it comes to the camera though.
I noticed you were doing this strange thing where the character's positions weren't absolute in battle. As the characters moved the camera would follow them, but the character's positions would also move relative to the camera and I don't think that looked good personally.
OH! Also, move the camera down a bit more during battles. The bottom menu covered up alot of the cool motion and action really often. The battles showed too much of the trees and upper side of the screen. There's nothing interesting happening there, so it felt disappointing missing out on the cool animations because the camera didn't center on the characters.
Regarding the adult aspect
Well this is a general controversial aspect to discuss. Everyone's got their own tastes and reasons for doing what they do, so I'm not going into that. I'm only going to talk about how I feel the adult elements were integrated into the game.
To be honest, I'm actually a bit disappointed with how long I had to play before I saw any adult aspect show itself. Second time I played, just to see whether the forest was randomly generated, I didn't experience any adult content throughout the entire experience.
Regarding the audio
I'm not sure I liked Jessika's voice actor too much. Maybe when I saw the image, I just had different expectations for how she'd sound. I think the voice actress sounded a touch too serious.
Mouse was pretty great though.
Regarding Exploration, I think retreating should allow you to keep all of your loot. At least have an exit area so that if you go all the way back to the starting location you can leave while keeping all the stuff you got. Also when you switch locations your character should appear the door of the location that leads back to where you came from in my opinion.
Regarding development, I don't think your enemies need a death animation. Your animator and artist is amazing, and I don't know how fast you work but death animations are only useful if the death target can be revived. Usually players can revive dead allies so they have a death animation. If enemies can't revive dead allies, then it might be better to just have them slowly disappear or flatten or something. You don't have to give yourself too much work.
Regarding combat, I really hope you don't ignore passive abilities and unique actives. Passive abilities are always running, but don't think of them as just stat steroids. Like Passive Ability - When health is lower than 50% strength is increased by 50%. That would be a good passive ability, but you can do some interesting things there too.
For instance, you can have the passive ability... ummm... let's call it Weak Chaser . Weak Chaser - When an ally inflicts a status ability on an enemy, teleport behind the enemy and slash. Or maybe Greedy - Attacking a stunned enemy has the chance to rob them of some gold.
Passive Abilities have the effect of encouraging players to adapt their play-styles and use different abilities.
Regarding the adult stuff. First I must add that I'm actually a really large fan of female assertive positions. I love cowgirl and all that, but I don't like this game's adult content because I'm not a fan of sluts, yuri, or the ugly_bastard tag. Ah... I should've said that earlier hunh XD. Yes... I don't like the game's adult content, but that's just a personal preference of course! Please don't let it color your perception of what I wrote. I did my best to be objective!
My suggestion regarding adult stuff would be to make it easier for it to happen and to not rely too much on chance for when it does happen. I think it's frustrating when your characters don't listen to commands even if they ignore to do sex stuff.
Maybe you have the option of having sex with the enemy at any point in the game as a different skill set. If you succeed in having sex with them you do damage to them and they might attack allies? Since I'm not personally invested in the adult content, I can't really say much here, but I will say that the game's very low in sexual content as of this moment. Anyway to make it happen more often, without it feeling like punishment would be good in my opinion.
Oh regarding input. I think if you're going to ask the player to use the mouse to traverse the HUB menu, you should allow the entire game to be played solely on mouse. Click right to move right and left to move left, use skills with clicking skills then the enemy. Currently 90% of the game can be controlled with the mouse and 10% can't. It's incongruous. PERSONALLY, I feel like you should also have 100% of the game be able to be controlled by keyboard as well, but that's just my preference.
I hate autosave only style games. Let me save when I want to, and load when I want to. As a dev I can understand doing autosave only for a demo (i'm doing the same thing lol) but yeah... PLEASE add it soon.
I won't be following the game as sexually it doesn't interest me, but I seriously wish you guys the BEST of luck.
EDIT: Oh almost forgot to talk about unit movement. This is one of the aspects of the game I didn't like during battles. When a unit attacksthey basically teleports straight to the enemy (which I don't mind at all actually for mouse - looks dope) but when they're done, they don't actually jump back to their starting position. I don't think this looks good.
The goblins throwing their bomb also looks bad. The bomb doesn't move in the air at all. You guys need to add some tweening for some of these battle motions.
I hope battles in the future give drops or gold in the future because right now there's no real incentive to seek out combat.
EDIT EDIT: Oh man I almost forgot. I should probably tell you but I found you through erodev if you're concerned about marketing. I'd also like to add to be careful with yuri content. Give players any amount and the expectation will be to include futa. Once you have futa fans though... they're gonna harangue you into including more and more of it. It happened to a dev my friend was following... What was the project called... uhh... LEWDMAZE! Yeah that's what's it was called. It's basically a futa game now even though you can tell it originally wasn't supposed to be.