i have two suggestions, though idk if they where suggested
1, alt scenes for some enemys,  mainly the super common ones and ones with niche scenarios. for example with the four enemys in game, the wolf should probably some variantion since shes in every room, while the rat is alot less common and probably doesnt need a second animation, though a cv scene with them would be fun, and im alittle bias since harpys are some of my favorite speices, but a stanard vore game over for them would be nice.
2, permavore mode, or just a hard mode with 1 life, could be as simple as that, but having cgs or art work for loosing in this mode could be fun, 

Hopefully you have an area for foxes and the rats because it would be a shame if niether had areas for themselves maybe some lore as to why you are in a prison in the first place?

1. Small, low-effort sprite variations for each individual enemy, so each time you fight another one, they look a tiny bit different.
2.  Instead of adding moderately-difficult enemies who have a few different attack patterns later in the game, like how some platformers do, I think you should make easy enemies with lots of attack pattern variants closer to the start of the game and so on. It's always fun progressing further into the expanse of the map with the promise of finding a new enemy, but adding some unpredictability to the same enemies we face every time spices the game up. 
3. Put a lock on the gallery you haven't already defeated or been defeated by :P

Add vore animations into the grapples based on % of HP. Full HP, just a grapple. 75% HP, maw teasing. 50%, head in maw. 25% Swallowed. 0%, full finisher. It would make the game more engaging and, overall, add more enjoyable gameplay for an undeniably vorny audience, as the only current way to get the content we want is to die. 

Give more control over digestion speed, as it happens woefully fast and is hard to enjoy. One moment, you're fully swallowed, then 3 seconds later, everything's already ended. Just letting players press Space to move on the stages of digestion allows for far more enjoyability from the players, and actually lets people see the work that's already been done. Win win. 

More dialogue would be great. Love the direction of each character having their own flare for things, so having more teasing/demeaning dialogue would be yet another boon for this game. Especially if given the addition of the character not instantaneously digesting. 

Don't put a lock on the gallery. Having immediate access to that is not only unfathomably based, but also lets people see the sheer volume of work put into a rather misleading v0.1 file name. I certainly didn't expect there to be as much content present as there already is, and being proven otherwise made for a delightful realization. 

Absolutely fantastic first iteration, and one I sincerely hope gets even more love put into it! The quality from even the very first version is astounding!

it would be nice to have some kind of map in the pause menu

I love the endosoma, and the unique quotes for it, really appreciate the detail.  a couple things I think would go great with immersion is graphite saying quotes when she loses, which can be digestion/endosoma specific for every mob or boss he loses to. also with endosoma the portrait model isn't changed in surroundings like it is for digestion. honestly this game has great potential, I'm excited to see where you take it, my favorite part is the cock vore scene.

     Hello! First of all, given it's the first time I see your game and is in its early stages, you got a very solid work already done! Congrats!
Very excited of how it's looking and to know the future of this game, it called my attention a bit when I read it was going to be inspired by Packetrat's game.
     Upon reading just how much I typed on this.... sorry for typing the entire Bible, lol.

____Feedback
     The general movement and animations of the character feels nice, nothing to really say there. Jumping currently has a fixed height, I'd say it feels better when it scales up depending on how long you hold 'Space'. The character struggles to jump down from platforms when moving, stopping you in place as if the game tries to move and stop you at the same time, and holding 'Down' doesn't let you jump off of all platforms you stand on (As in, if theres two platforms ontop of eachother, you cant just hold the button to pass through both).
     

     Very nice aesthetic/visual style. Specially for a solo dev project, this looks pretty neat and should not cause you much trouble compared to other games, you could even make slight variations on the tileables and some objects for depth, subtle guides for the player (we are yellow tape HATERS here) or to identify different areas. I've read about your level roadmap from another post, and I'd be careful to see how each area links together. No idea on what the lore or script is for the game, but never hurts to point that out.

     Basic attacks seem to not do much damage, sticks you in place for a long bit and are spammable, enemies are flung off from the attacks, its sound effect isn't very pleasant to listen to after a while (sounds like shattering glass), and I find no reason to hold my attacks. Making combat a bit faster and "free" could benefit you in the long run, specially if you are planning on adding new mechanics afterwards.  It can grow a very toxic/unsatisfying behavior of just standing around smashing your attack button, which will be an issue in boss fights. I recommend checking other metroidvanias and side scrollers, if you are scared of the controls getting too difficult for keyboard users... using the mouse buttons for combat doesn't feel bad at all in games.

     Very nice menus, there's already a lot of accesibility (If we can call vore fetish tags as such lol) and is completely functional. Given how -Sharp- all the graphics in the game are, seeing the font be slightly blurry feels off, like I suddenly changed my screen resolution. I would recommend having one/few tags for certain sounds like screaming, bone crunching, crying, etc. (if you ever plan to add those in the first place)

     The game feedback when interacting with enemies is a bit too little in my opinion. Perhaps this is probably because of this being an early demo, but it's still nice to mention. A hurt/stunned stance for enemies would be great, specially whenever you jump/struggle away from a grab (Currently, enemies either switch between walk/idle animations, or just stand still).  The player could have more sounds, like landing on the floor, jump, footsteps...

I'd be careful with the "Metroidvania" side of the game, the backtracking. The area with the elevators/sliding platforms forces you to wait for them to come down every time you wanna go up, which is slightly annoying with how slow it is compared to going down, which is simply jumping off the platforms. Either make the platforms appear already at the bottom when you activate them, or make it so you can easily toggle the elevator position while laying the map out... basically make it feel nice to go back and forth. Speaking of maps, one would be nice but I've seen you have one in the elevators area, so making sure there's a few around as quality of life would be great!

____Bugs (Or seemingly so)
     Player is capable of landing hits on enemies behind doors, and I imagine walls too (though this is impossible with the current level design).
     Boss fight music won't stop after beating them (very minor since you can simply leave the area or reload save, but still).

     After escaping from struggling, you have invincibility for a few moments against that enemy. That doesn't happen when you are close to another. You can easily end up locked between two of them.

     The plant enemy can be escaped from without receiving damage. Might not be a bug, but careful in case you want to make a platforming area with a bunch of plants below, players could potentially just jump from plant to plant without loosing hp at all.

____Suggestions

     Given how big areas are, I assume there would be upgrades like double jumps and other possible movement mechanics. Perhaps enemies that could attempt to vore you from a distance could be cool in these cases: A frog sticking its tongue on you and having a struggle mechanic to pull away while it drags you, a spider lasoing you in the air, a suspicious jackalope doing voodoo doll vore on you if you stay in their line of sight for too long... I've read you dont want a struggle system, but the current one is a bit too forgiving, perhaps you can make something more similar to the game Echidna Wars DX, or just quicken the struggle system (Eg. Movement button appears on screen, press the right one quickly enough or you are getting caught)

     Speaking of enemies, you could even make certain ones that can appear in any area just to mess around with people. Slime mimics that hide as objects from the map, additional ghost enemies appear in areas you die a lot... (though these kind of enemies can do for a whole area/level of their own).

     Zoom out the camera a little bit, or make it adjustable by the player. Not only this means some can zoom in to see all the    d e t a i l    but so it doesn't feel too claustrophobic. Specially helps if you are planning on adding ranged enemies, can mess with the level design though, up to you if to adjust it at all or make it a slider for the player to mess with.

     If you need more ideas, I honestly think you can take inspiration from SCP and the game Prey. Its gimmicky type of creatures make for great inspiration for enemy concepts, and you can see it in multiple games already (Enemy that approaches only when you dont see them, slow but unstoppable enemy , sound based hound,  hacker placing traps around...)

     Dont forget to give some love and care to the sound design, it can really give the punch to a lot of things, and be the reason why some elements might fall flat or not feel as impactful... for example, ambience music.

     I am a huge fan of modding tools, but I haven't seen a single project try make mod tools for Godot games, so this isn't much of a suggestion but rather a thought. If you are able to find anything about it, or even create it, that'd be sick as f**k.

     Repeating myself a bit here since I do talk about this in the feedback section, but using the mouse for stuff like attacks feels way better than having everything on the keyboard. You might not use it to move a cursor around, but it's more comfortable in my opinion.

Will there be any sort of 'struggle' system when you get grabbed or is it always intended to just jump out with space bar whenever?

I would like there to be a dash like Megaman to make the gameplay more frenetic, I would also like the enemies to have charges and more attacks

I like the boss to have ranged attacks that leave you stuck and hits at short distances.

and also that you could read the posters because the lore, I'm sorry, will be very good

along with an npc appearing at the beginning to help you escape and this explains the tutorial

I wonder if there will be safe vore in the game.