UI and Menus

While I am a fan of the traditional HUD, I don't think it would be detrimental to the atmosphere of the game if the design team went for either a minimal or no HUD approach. One of my all-time favorite titles is the first Dead Space game and they went in a bold new direction with real-time menus (no safety from ravenous Necromorphs within windowed menu screen now!) and no traditional HUD. Health was displayed on the back of Isaac's suit in an easy to see and understand format and your ammo counter was large and visible. I am not certain that the same concepts will apply well to Bloodstained, being an RPG, but perhaps the health and MP bars can minimize when there are no enemies onscreen or you are not using magic power.
However I would love to see dynamic character portraits during dialogue. In my opinion it's really just a nice touch to see that the artists went the extra mile to make the game a more cinematic experience.

theres a huge problem with realtime menus, they work fine for games with a very small inventory and few options, in a game like this with a huge inventory and lots of menus to go through realtime falls apart very quickly

i can however, see the merit in a quickmenu or quickhud, where you set up 2 or 3 'outfits' and switch between them in realtime, or a quickmap where you bring up a backgroundless map that displays over the action (possibly with a menu option to zoom to the surrounding 20x20 'squares' to show the surrounding rooms or show the whole map) and have these elements parented to flourishes in the corners (to make it look like a picture frame)

for instance, you have your traditional HP/MP/Status in the upper left and have a hide/show option in your start menu, whether its showing or not you still have the flourish in the corner, just not the meters.
you have your 'outfits' in the lower left, and only see the flourish till you activate the menu/swap.
in the lower right you have your 'menu corner', whether that entails a minimap, just the flourish, or the quickmap coming from there. <YES YES YES i want this, i check my map constantly
upper right i guess would be the wild card, maybe you 'favorite' 3 use items like potion, tonic, and peanut, and then can use them with a couple presses rather than opening the full menu or quickslot spells to be cast.

it does need to be said though that while these options would greatly speed up the feel of the game, the quickitem and outfits options do have a potential for game breaking (the outfit not so much as its been implemented before, but quickfiring off high mp spells then quickuse high tonic, while an option you as a player can choose whether or not to ab/use it does need mentioning the potential pitfall of it)

and then of course you have your filligreed Iga menu screen of awesome, with its item, equip, map w/ markers, checklist, options (including hud settings), and whatever else they can fit in ^_^

i do love this, perhaps those can pop up from the lower flourishes ^_^

Well, when I heard quick menu, the first thing that popped into my mind was something that could be accessed instantly through shortcuts. Like the items assigned to buttons in Zelda games.

That sounds more like an "equip" slot to me than a quick menu. Anything that can be assigned to a dedicated button would most likely be something you equip. A quick menu would be the interface that allowed you to, for instance; press and hold a button to bring up a group of items that you could then quickly switch between.

essentially, what i mean by abusing quickmenus is more a pacing issue than a design issue, like you quicktrigger your mind up spell, spam your heavy attack spell and then pop a high tonic all within a few seconds, all without stopping to allow for the enemy to attack or even move, that could very easily make bosses and hard enemies trivial

if a game is designed for that playstyle (mmos usually, and it balances that with massive hp, cooldowns, and a shitton of things to cast), then its not as big a deal, but in a game where youre supposed to dodge, attack, maneuver, get in a few hits and a spell, and if you get hit enough you have to scramble to use a potion it gives weight and flow to a combat, and a feel of panic when youre at 2 hp and youre rifling through your menus looking for your potions even though youre in no actual danger of dying inside the menu, being able to hotkey salvo utterly destroys that feeling, so it is a mechanic that will have to be looked at very closely and weigh how much it will change the feel of the game, and whether that change is for the better or not

like the difference between going through SotN wih a sword and shield as opposed to duped dual bat pentagrams, the difference there though the dupe isnt an integral game component and you do have to save up to get the duplicator and grind/find two 'nuke' items, its not just handed to you at the start as part of a quickmenu

Seeing the Red Bull article on the game reminded me of a related point I wanted to bring up. Didn't want to make another topic for it since I remembered this one here was a thing.

I want health and/or MP bars. Horizontal or vertical, doesn't matter, though horizontal does tend to obstruct less of the game. The actual colored bars give you a much faster indication at a glance of what your current health/available MP is, and you know instantly how much damage is done from how much was subtracted from the bar. Everything being numerical in the top left just comparatively seems...a bit too mechanical? Colorful meters just provide that old school feel we want from a game like this and are more easily seen. SotN style with numerical health and an MP bar is okay, too...I mostly just want one there lol, and can live with one of the stats being all numbers.

I don't see why there couldn't be multiple options here/the ability to auto hide the UI, but I personally wouldn't mind it just always being there either. Some games are great with the minimalist feel for immersion, others are more enjoyable when they feel more game-y. For me, this is probably one of the latter, as the genre has been in the past.

I can't imagine how a purely no UI would work in a game like a metroidvania (though if they figure it out and make it work well then I'll be quite impressed). I personally like the idea of a fading UI for when there are no threats nearby but I also wonder how likely that is to be. Igavania's have some sort of creature in nearly every room. Maybe a fresh option would be to display changes to the stats as the changes occur like -poison in green text to signal you are cured of poison, a colored bar that deplete's over Miriam's head when her hp or mp drops accordingly, a special effect (like Alucard's glow) when her mp is back at max. Nothing wrong with a classic hp and mp bar in the corner either.

Perhaps spells could have a cooldown period before you can use them again, like in Xenoblade Chronicles. This would keep players from spamming them if the quick item use includes items that restore a lot of MP.

As for menus in general, I recommend checking out this video from William Strife for some examples of how various games handle their menus and how these choices affected  gameplay.