Cheers. Hope you're taking care of yourself.
Looking forward to what you come up with for the romance system eventually.
Since you asked for suggestions, here's some things off the top of my head (hopefully not too ambitious)
- Assuming Mal0 isn't the last alternate entity, it may be interesting to have a mode where you're chased by both of the girls at once (or more if there's more girls planned for the future), though that may require larger maps to have enough space to avoid them all. But I assume Karelia is the main focus here for stuff like the romance system. I also feel like regardless, the game would benefit from having larger maps in general with more exploration and optional things to do in them (there's not many puzzles right now despite the difficulty settings implying otherwise, and adding more to the current maps may make it feel a bit too dense and not like the backrooms)
- Similarly to how I expressed before that I'm glad Karelia's wonderful model finally has a solid game tied to it, I feel like Cryptiacurves' Beast Darling would fit really well as a third model option. Regular ink darling is already in the game, albeit as a non-enemy NPC, so it's not entirely out of place imo.
- More unpredictable behavior and patrolling. I know this is likely coming with the rework to her horny levels but figured I should mention this too. Maybe she starts hearing your footsteps when you're sprinting at a certain level, or when you lose her she still has your scent and *roughly* knows the general direction you ran off to. Maybe she starts camping the exit once she becomes aware you've taken the ladder (if she passes next to its original location) so you have to kite her around it. Or maybe she could occasionally stay still when detecting you and start masturbating or something at a certain level, luring you into a false sense of security thinking you can approach and watch, then when you get too close she breaks out into a brief sprint that's much faster than normal, I dunno, you can really go crazy with the concept.
- More ways to interact with the environment. Stuff like the optional lube sidequest really does add some stuff to do in any given run I feel, and more of that would be really nice. Maybe you could rewire the alarm trap to tangle her leg for a bit or something to stun her for a few seconds, which may take longer to do than disarming it. Or disarm beartraps without stepping in them. Or set up a camera in one spot that you can look through at any moment to check if she's there (or help with certain memory puzzles). Though as mentioned above, I feel the current maps are just a biiit too small to add too much density into them without breaking immersion.
A lot of these I just made up on the spot without much thought on how they may affect the game long-term, but hey, ideas are ideas. Here you go lol.