(PS: I ended up writing a wall of text, kinda sorry but I hope it's useful, I REALLY enjoyed the demo and really want to do something helpfull!! ^^ )
The Demo is very promising! Very chill game with great art-style and animations.
MY FEEDBACK and SUGGESTIONS
- Art and Animations
I hope to see variety in terms of sex animations (I'd avoid doing "samey" vaginal and blowjobs with too similar positions), maybe take advantage of the animals having different natures to come up with a good variety of scenes: Bunny Girl is about service and being more submissive, Frog is into blowjobs and licking, Fox enjoys turning the protagonist on with teasing or something like a reach-around handjob, and hog being more dominant and physically restricting the protagonist.
You are the artist and you should feel free to draw whatever you want but, to get more people playing (and supporting) the game, I suggest exploring different body types (while keeping most of the characters to your likings): like characters with not-so-huge boobs (not an issue for me personally, but I could see how some players may lose interest in the game if not into big boobs) or less/more muscles. You could also add 2-3 characters that always stay together and look the same (maybe Bee/Wasp-Girls? or a Queen Bee being the character you interact with but she makes her servant serve you) to more easily introduce three/four-some scenes (like, for example, by having three bee girls licking a dick, you can make the two on the sides specular so you just need to make one animation and just mirror it, or maybe have the player fuck the girl in the middle and finger the other two on the side, so you can just copy and paste the same animation three times and MAYBE just slighlty change the face). Basically, since you have limited time to animate and develop the game, you can sneak in more content by being smart about how and what you animate.
- Gameplay and QOL
I think you should add a button to hide text during scenes (maybe I missed it?) and a way to access a character scenes by interacting with them or through a gallery menu (or both). My biggest suggestion is to add some sort of "DatingSim-like" element where you usa an "action token" (start with 1, you get more by leveling up and they recharge on sleep, I think it's better than just using stamina) that you can use to play a mini-game* with a MonsterGirl to bond with her, which unlocks dialogues to give the player more flavor about their personality and levels up the "Relationship Level" with them, this system could be expanded by having a unique shop for each girl with scenes and portraits that are locked until you reach Relationship Level x, then you also need Gold to buy them. Maybe also allow the player to unlock variations like recolors, different piercings (or getting rid of them) or maybe different eyes during the animation, or whatever you know doesn't require too much work (I don't animate so I don't know) but can add reason for the player to make progress.
*MINIGAMES if you can, you should make a unique bonding Minigame for each girl, but even just one could work, Minigames should be something chill but with an harder mode for someone looking for some challenge, here two ideas (but generally, either doing something to the girl or having her do something to you):
- Giving a massage (point and click): the player starts by massaging the girl's back (either just a still image or a 2 frames animation for breathing + 1 frame for a perfect click, something like stretching and a light ahegao face), green dots appear around her body that the player needs to click, the dots slowly shade to red before vanishing, the quicker the player clicks on them, the more Bond points they get. By reaching a higher Relationship level, the player unlocks "Phase 2", or harder difficulty, where the girl is laying on her back and the player gets to massage her breast and thighs. Dots appear faster, fade faster and the player can fail the minigame if he doesn't get a minimum amount of points, but each dot give much more Bond points, which allows the player to bond faster while spending the same amount of "action tokens".
- Trying not to cum (Pressing Space with the right timing): this definitely suits more a dominant girl, basically she gives the player a handjob (that will later become a scene you can watch on her gallery, so you can reuse the asset), a bar on the side or bottom of the screen slowly fills with white and the player fails if it fills completely, meanwhile he needs to press space at the right time during the animation to resist, to help the player understand the timing you can add a bar with Green, Yellow and Red spots, green is either in the middle or at the right end of the bar, obviously: hitting the red spot fills the gauge the most while hitting green fills it sligthly or doesn't at all, also green zone is the smallest and both green and yellow zones get smaller in harder phases. The emptier the gauge, the more Bond points the player gets. You could either make a different animation for a harder version (like blowjob for phase 2 and a reverse amazon for phase 3) OR be smart about it and just add elements to it: Phase 1 - Reach-around handjob with the right hand; Phase 2 - Handjob gets faster and she plays with a nipple with the left hand (so you need to just add the arm animation); Phase 3 - the girl also licks the protagonist neck or nibble his ear. This way you can add depth to the animation, have 3 phases that feel different but you don't need to put in the time to animate 3 different scenes, just one that unveil itself slowly.