Great work on this! Really looking forward to see how this project develops. After going through (what I think) is all the content, I have a few thoughts on how this game could be improved:
1: I think the biggest issue right now is that both the player's and enemies' damage is too high. Ideally, combat should last long enough so that the player can see all of the different scenes/attacks for a given monster, but I often found myself either defeating an encounter in one or two hits, or being defeated just as quickly.
This was most noticeable for me during the Alraune fight, where she can easily deal half your hp bar in a single hit at the level you are likely to find her. Even with Lulu's healing, you will not have time to deal damage until you are high enough level to survive at least 2 hits without healing. However, once you reach a high enough level to do this, you are doing enough damage to defeat her in just a few turns.
My suggestion to fix this would be to change the way leveling scales your health and damage so that your health is greatly increased but damage is greatly decreased. This way, fights can last longer and the player will miss less of the content by ending fights too quickly.
2: Another, much more minor, thing that could be changed could be the ways grabs work. Currently, a monster girl may try to grab you and force you into a stance where they deal increased damage. While sufficiently erotic, this mechanic is entirely avoidable by simply blocking when the game tells you that a grab is coming.
While this might be intentional, I think it would be better if the grabs worked in a way where your level helped determine your success in escaping the grab. One idea would be to have it so a grab has a higher chance of success the lower level you are compared to the monster girl. Maybe have it have a base chance of 50% if you are the same level, and then have that increase/decrease depending on how many levels above/below you are compared to her. This isn't necessarily the best way to do this, but I think grabs should be harder to avoid someway regardless.
Anyways, those are my thoughts! Great job on this game and I look forward to seeing more content for it!