Greetings.
So, I just finished my first playthrough and I REALLY enjoyed the game. It took me 42 hours and sure, it has a lot of things that I feel that are unnecessary and some bad decisions to which can be solved with a simple option: Let players choose what kind of game they want to play, be it a DOS influenced BG or something "less creative and more boring".

So, what is a "hardcore" 5e mode? Basically, RAW PHB 5e. Some changes that really bugged me were:

-Everyone can use scrolls.
-Wizard learn spell from any class (via scrolls).
-Cast 2 spell (non cantrip) as action and bonus action
-Cast 2 spells with haste
-Off hand using modifier on damage, not on hit (without fighting style)
-Knockout damage too low. (Instead of an action, should change it to a toggle button)
-High ground and ranged. High ground is broken.
-Backstab.
-Shove as bonus action (missed an attack? Try shoving as bonus action and win anyway. Kinda op.)
-100% chance to hit.
-Help action doesn't give advantage (maybe change Help as implemented to "Use medkit")
-Changing weapons without resource (equip longbow, shoot, equip shield OR equip staff, use special feature, equip shield)
-Magical pockets.q

And, honesly, it was fine. It was a fun experience and those changes even felt right at sometimes, however, some of us might've wanted a more... traditional DnD experience. So, instead of creating a hard mode where enemies has more hp and do more damage, why not change a few rules when starting a campaign? I know theses changes aren't hard to implement and everyone wins with more options, especially on a game so subjective as DnD.

Other than that, there are a few things I'd like to discuss:

-Add 2 Short rest or full hp single short rest. A single short rest where replenishes half hp doesn't feel right.
-Add Dodge action. Why not?
-High Ground and backstab is op. Maybe give it a minor bonus such a +2 to hit.
-Separate Disengage from Jump. I'm not a frog, sometimes I just want to get away without jumping.
-Add Shield and Spiritual Weapon. Those are staple cleric and wizard spells and there are no reasons to not implement them both.
-When combat starts, every character should roll initiative if near the combat, (even if hidden) otherwise some exploit may occur.
-Fix AI. Maybe a threat system? Don't know. Feels awkward that every enemy wants to kill the mage casting fire bolt while a fighter is killing at least 2 every turn.
-Too many surfaces. Also, enemies have too much throwable for the enemies.
-Too many surfaces. I mean it.
-Make battle log more explicit and add time. Show the roll before using mouse over, for example:
10:00 - Worg used Bite (Rolled 7) on Gale.
10:01 - Worg missed Gale / Gale was hit for 8 damage.
-Rest should be localized. Long resting on a dungeon? Err... nope. The way rest is implementent breaks the immersion and feels like a cheese mechanic. Respawn enemies when long resting is also an option.
-Candles are op. You know what I mean.
-Target character portraits. Again, easy to implement and really needed.
-Level Cap, at least 15. I know most campaigns end at low levels, lower levels are the most interesting and it's hard af to plan high level encounters, however... Most of us never played a single campaign where we could achieve level 20, so games like this are the only way we can test those characters at high level.

I feel this could be one of the biggest games ever made and I trust Larian to make the right choices.
Thank you all for reading and I hope this feedback was useful.