I wasnt planning on actually posting with this account, as I would have much rather sent a PM to you, but since that requires at least 3 posts I figured I'd give my input on this anyway.
Well, I know what I want to do for the game. I am lost on trying to figure out what my players want. As mentioned before it's impossible to please everyone, but it appears there are two camps. One that wants more gameplay, and another that only wants me to focus on the sex sandbox.
Although there's a clear division with the majority of input you're getting, have you considered trying to integrate sandbox-like options into the core gameplay more, rather than keep them relatively separate? I'm aware of how difficult this could end up being but it might help work as a middle ground to see what side weighs more. The goal would ultimately be balancing both aspects in the end anyway, but it could lead to additional creative opportunities with how you utilize the sandbox in the gameplay itself. Keep in mind I'm just here because I enjoy playing in-dev games to give myself bug tracking practice so I don't get rusty, as my job is QA so any practice is good practice.
My wording on this is probably strange, but an example I can suggest is allowing a method to modify NPCs to the players liking, or to meet some quest specific requirements through a temporary or permanent method. Player sided content is covered quite well, but NPCs on the other hand aren't as flexible
A way you could approach this is with magic potions (or some other thing that's more interesting). You could implement a system that allows you to give these to NPCs to affect them in various ways like making them taller, shorter, have a bigger ass, have smaller tits with both minor and radical amounts of modifications.
This would allow players to have some form of flexibility with what they want in terms of sandbox material since you can alter the other characters (or maybe your own on the fly) to however you desire, while also providing a gameplay mechanic that could be expanded into adding quests where you can only access some zone if your character meets some requirements.
At this point you could branch off into how youd want to go about this, where maybe theres an NPC that wants a potion to get bigger tits, or wants to have wings or something and if you do this you're rewarded with unique positions that can be used later on like a double vaginal threeway or something, which can then be used for capturing multiple creatures in the wild, but makes the encounter tougher to beat.
This could be further expanded into the breeding aspect/monsters to breed to both allow the player to modify whatever creatures theyve captured to however they want them, while also allowing the doors to be open to other mechanics like it. Or hell, maybe doing some specific quests could grant your player some outfits the NPCs wear or something.
The main reason for suggesting all this is while talking to an NPC to customize everything on the player helps, a more on the fly solution might be good for NPCs or captured creatures should the player want something different. It can get pretty tedious in the sandbox, so a solution to speed things up with enchantments may help for gameplay and pacing specifically as well as the overall player freedom for customization.
Again I'm not trying to push you to do anything, but rather get offer some direction on creativity to appease both sides of the feedback you're getting. Doing what I suggested is a gargantuan task, and would take a very long time to get right let alone setup to even get started so
I'm by no means saying do it for that very reason. I just do QA, and part of my job is give constructive feedback to improve things if possible though I mainly just make sure things work. Your game has most of the groundwork there to go any direction you please, I just know that these things also take a lot of time and planning. Do what you feel is right, since there's multiple solutions to this issue, and any of them can be beneficial. Anyone can also openly disagree or agree with any point of this post as well.
Whatever the case, good work my dude and above all do what you wanna do most. Just be sure that feedback you receive doesn't get to your head. Just try to think creatively on how to please both sides, I'm sure you can get the idea.
Also I got interested with underwater aspect of this and found a spot with a small hole at the bottom of the underwater terrain that leads nowhere and seems really out of place from the rest of the terrain geometry, and wanted to ask what it's about. It's near the glowing seaweed but out in the distance by an alcove. Also I ended up swimming for like 3 hours under the map. You can do a hell of a lot of travel in the water so I'd suggest adding in some boundaries for inland terrain to prevent swimming under the map.
