As far as I know, most of the item/object interaction can have issues due to the way the game registers that you are actually looking at it, you have to generally aim the camera and the character herself in a particular way for it to work sometimes. If on the other hand you are simply running into issues where these objects can't be used at all, even with some camera/player movement, then not sure what to say there really, the only bugs I've run into myself so far that are game breaking is that if you begin sprinting too quickly after aiming and using the reload animation, you'll be caught in a permanent looping animation of Julia reloading her gun, only has happened to me twice but was super frustrating when it did since it means your stuck walking for the duration of it, and I'm not sure if getting hit or other things that would force an animation would fix it, though I imagine they would. Aside from that, just the occasional fatal error that causes the game to crash, but that has happened once so far. Will say though, I definitely do hope the camera or item pick up issue gets solved, maybe broaden the "field of vision" Julia has so she can more easily interact with objects and items.
Infection itself actually seems pretty neat as a mechanic overall, it basically makes your vision more disoriented the more you are exposed to infection, whether thats all in one go or just repeated exposure, and well, the obvious effects of inflation slowing you down the more she has stored up inside her. Its possible to get the former effects though before the ladder if you just let a single zombie go to town, which actually doesn't really have any negative effects outside of making vision more blurry and your player character run slower, kinda neat overall really and could lead to some interesting mechanics/scenarios in the narrative and gameplay wise, having herself a MUCH easier time by trading her dignity for a better chance at survival. Lots of possibilities there in the end honestly,and could lead to possible virgin/corrupted runs of sorts, though not sure if it'd be something worth focusing on since the unlock system and speedrun/kill all enemies element of the game will already be a strong reason to actually play well versus just letting her get fucked by anything and everything.
Also have to say, visually the game is pretty great, and love the choice to add a bit of character customization in costumes, and even beyond with accessories and hair! Honestly not sure why this isn't something the actual series itself has ever delved into, though generally having varied costumes has always been handled well so never been something I really thought of till now honestly. Gameplay could probably use some more polish in certain areas so its more attractive to more people, like the option to use the mouse to swap items in the menu, even if I find it pretty fine to use the shortcuts/combine options on the fly, its a small detail but I do really enjoy the ability to combine ammo in the menu with your gun, skipping the reload animation and sometimes helping you avoid a hit in a tense situation. Gunplay can be a bit awkward at first, but once you get a handle on things it becomes pretty satisfying, and even sort of implements a damage buff when standing still and taking your time between shots similar to the Remake as far as I can tell, honestly between that and the big bois I'm certain I can say this has now been inspired a bit bit by the recent Remake, which is a good thing really, blending action and horror, and well in this case lewdness too. Mostly just needs some polish and I think the gameplay itself will be relatively fine as a base, melee moves or not, the idea enemies defend their head as well, but can have their arms broken by well placed shots is pretty neat, could be something to include to the legs as well if you choose to go with this rather then really going for reactionary shots/melee moves as the system for that also seems to be in place as well. So far a really good job replicating a RE5 style vibe, though definitely a bit more creepy and all around a tad more difficult just due to how hard enemies can hit when you have no clothing/less clothing, and in general how quick the enemies can be, almost to super human seeming levels when you're running from them and they give chase.
Biggest cons I can think of currently is the obvious lack of a save, or well, checkpoint/chapter select. In this case at least it only REALLY hurts due to the fact that like others, I find the start to be a bit of a slog to get through, even if I do like the idea of it still quite a bit honestly, it can wear down on ya a bit in repeated playthroughs. Not saying it should be something you should get rid of in the slightest, and even once you are finished with "Arena" and move onto the main game, something similar with a bit more space and dimensions to it could be pretty great all around, that or a situation where you are pitted against a relatively powerful, not indestructible but incredibly hard to kill enemy in a relatively restrained area could be pretty interesting really. Next really would just be the outside zone, as its by far my least favorite just due to how easy it feels to get lost within it, and without knowing that you have to interact with the gate to spawn the enemy who holds the key, you could wind up killing most if not all the enemies in the area and still be stuck out there. Wouldn't be nearly as bad as long as their was some indicator on where to go, or if perhaps you could even see the manor in the distance or something akin to that, but the open ended nature of it (at least seemingly) and lack of real direction kind of makes it difficult to really map out a path through their from time to time, especially on the first few times through the game. Both of these really wouldn't be an issue though if I didn't find the manor itself to be the most interesting area yet, the ambiance in it and even what seems to be the theme to a save room on the eastern hall is all pretty great, and the only thing holding the manor segment back I feel is the navmeshing bug mentioned on the changelog, allowing only certain enemies to move at certain times, its the same issue for the outside zone really as well and hope it something you can manage to work past as I can imagine both would be far more tense and difficult if I couldn't just turn a corner and shoot an enemy without it being able to really defend itself. The hall ways are kind of a mixed thing for me in the manor itself though as they seem almost too narrow, but in a way that does help to recreate a more isolated feel, and definitely a claustrophobic one, so good on that, would be even better if an enemy were to occasionally be placed in one of the rooms or if some could follow you through the doors, though having said that I haven't really given the basic enemy type a chance to do so so they MIGHT be capable of doing just that for all I know.
All around, I think you guys are kind of on the right path to something pretty great here honestly, its definitely hitting those itches I've had for so long to have a proper RE H-game in the past, something that's been left longing for awhile ever since Resident Evil Progeny kinda fell off the face of the earth, though this definitely goes well beyond what I expected to ever get considering its 3D and actually looks pretty well made, and has the potential to play extremely well too. All in all, hope the break is easy on you and that you continue to strive forward in improving and further developing the game!