(First of all, sorry for the English, I'm not a native speaker and I'm using the translator)
First of all, the game has a lot of potential, and watching this game reminded me of old programming classes I had on a similar engine that I had to stop... but this game revived my desire to create games (nsfw or not) and I did a thorough analysis of the game to try to help;
Basically, the problems with the gameplay are currently the lack of combat variety and minimal difficulty, like I did a test and most of the game can be passed running if you have skill and the enemies can be easily eliminated.
I know these problems are obvious since it's still v0.1 but I suggest you focus on the gameplay, mechanics and game style before creating new enemies and levels, because what differentiates an adult game from adult content is the gameplay that comes with the content.
I know you're making the game your way, but I have some ideas and mechanics that, if implemented in a specific order and preferably before you plan and create the rest of the game, will enrich the player's experience. (The phrase, "I came for the +18, I stayed for the gameplay" is famous in my online friend groups)
During today's work, I ended up thinking about this game and imagined some systems that would add some new mechanics and styles, along with covering up the current problems like lack of variety.
But I'll just talk here about the main ones that I think you might be working on something similar:
-Stamina/resistance and escapism.
Basically it would be like this:
We imagined Sewer rat (I don't know why, I loved this character, my favorite so far, although I don't like scat.)
He grabs the player, at that moment he tries to vore the player, who uses his arms to try to avoid it.
At each animation loop, the Sewer rat tries to suck the player, using up the player's stamina, who tries to avoid this. The amount would vary depending on the enemy, let's say 2 at each animation loop for the Sewer rat.
If the player doesn't press anything, he is sucked into the Sewer rat's hungry ass without any resistance or much stamina consumption (maybe the player wants to test fate, new mechanics, use an item that is necessary to be inside the enemy... it's up to you), but to get out, more stamina will be needed than to avoid being swallowed.
And if you want to make the game challenging, make the stamina have a limit on how much it can regenerate, like:
Start the game with 100, but if you escape from several intestines, it only regenerates on its own up to 30, thus forcing the player to be strategic, avoid groups or waste stamina because as they try,
let's say, stronger enemies take more stamina with each loop and require even more to escape from inside them, thus perhaps opening the door for a stamina upgrade mechanic.
In short, that's it, I had several ideas, some that worked in synergy with this mechanic and create new ones in an optimized way, but hey, I'm just suggesting, of course the game is yours, but if you want more ideas and/or help, just let me know, but of course, I hope you keep up the great work.
Anyway, sorry for sending a long message late at night, anyway, great game.