A quick preface, I want this game to be great, and it has the potential to be just that. I have put in around 95 hours thus far on multiple classes and characters trying to get a full idea of how the systems function and experiencing a full breadth of dialogue choices. So far the game is incredible. There is so much depth and replayability, most systems are well implemented and make sense.
I'll start off with the 2 that are probably the most common among posts I've seen.
Rethink surfaces. I have had the druids in the grove start an entangle on fire and the battle becomes a flaming hellscape that never ends, because every time they cast entangle again it reignites the entire area. It also feels bad to have a low HP character actually dodge a firebolt but know they are dead on their next turn because they are standing on a fire surface, or even further, that they are also burning even though they dodged the spell itself. This is true for ray of frost as well, and makes cantrips incredibly powerful for no investment in a spell slot.
The rules of advantage any time you have high ground or are behind the target make certain instances of the D&D ruleset feel very unimpactful. This leads to unexciting gameplay situations where the player is trained to ONLY think about how to get a height advantage or to use half their movement to circle around an enemy every turn. Also, this makes spells that require enemies to make saving throws simply worse than ranged attack spells or shooting bows because you can easily achieve advantage on those rolls. Advantage should be something that is slightly difficult to achieve or it cheapens the usage of spells like guiding bolt, or attempting to attack from stealth (which with the power level of things like jump and shove would be a better feeling decision point as far as action economy)
Many feats are not fully functional - great weapon master not giving additional attack on critical, dual wielder not providing additional AC. Mobile does not prevent recently struck enemies from making attacks of opportunity every time, and when it does it often burns the enemies reaction and the attack doesn’t go off.
Allow options to see all dice rolls after checks are made - at the moment you aren't able to see what you rolled on the dice for things like unsuccessful saving throws or skill checks in the world. Perhaps have an entirely separate combat log tab that shows all of the behind the scene dice rolling instead of having incomplete information in the single combat log as it is now. PIggy-backing on this point to include that when rolling with advantage or disadvantage both rolls should be available to be seen also, even in dialogue encounters.
Instances of imposing advantage or disadvantage not functioning - the main one that comes to mind is the protection fighter not giving disadvantage to attacking enemies when an ally has the buff.
Hunter's Mark and Hex both do not apply double dice damage on critical hits.
Colossus Slayer for Ranger activates even on full health creatures, and sometimes does not activate on wounded ones.
Casting light on a characters weapon does not give that character (or other characters) vision of targets so far as to remove the disadvantage of attacking something that was previously obscured by shadows. Dancing lights does provide light and function correctly. On a side note perhaps starting Gale with either light or dancing lights would be useful to newer players so they could experience the spells during the mini darkvision tutorial in the ruins.
Great weapon fighting is not re-rolling 1's and 2's. POSSIBLY only when used in conjunction with Battle Master attacks.
Quarterstaves should be versatile weapons and/or be changed to 1d8 when wielded 2-handed.
If burning is kept in the game, it should shed light similar to a light spell. A target shouldn't be able to be burning and still obscured by shadows.
In the druid grove when talking to Nettie it might be useful to allow the player to roll an insight check on her to reveal her intentions of poisoning you, or a nature check on the branch she plans to use. As it plays now it leaves the player very little choice as to the outcome of the situation until she poisons you.
The loading property on crossbows does not seem to be implemented
The disadvantage on stealth checks while wearing heavy armor is almost non-existent due to their being no stealth checks associated with sound. Hopefully there can be sound detection implemented.
While having the dual wield slider checked occasionally you will attack of opportunity with both weapons.
When drinking the potion given to you by Priestess Gut and choosing the race response as Seldarine Drow there doesn’t seem to be a resolution to the scene and Gut attacks you as if you had betrayed her.
When enemies turn invisible you can still see their outline with AoE targeted skills. Invis enemy AI can use some work also, they will often go invisible at the end of their turn or do so and not move at all so they are easily spottable.
Lighting during stealth gameplay is very inconsistent. There are areas of maps that have well-lit sunbeams where it is registering as fully obscured, and other areas that appear dark where it is recognized as a clear area. The rear of the Owlbear Cave comes to mind (ray of light that registers as dark), as well as the elevated areas in Priestess’ Guts room (registers light where there are no nearby light sources).
Would be nice to see Javelins as throwable weapons, and also ranged attack options for handaxes.
When creating stacks of boxes to jump to higher up areas, you cannot jump back down onto said boxes. Perhaps a good spot to require acrobatics checks to see if the boxes break when jumping back on to them. In general should require acrobatics checks when jumping from higher areas to mitigate or eliminate fall damage.
Don’t allow Wizards to learn spells from other classes. Currently Wizards can fill the Cleric role and have more spell slots due to arcane recovery, that feels like a big flavor foul to me. I’d prefer if scroll usage was also restricted based on class also, but if that’s a video game design decision then I can live with it. Additionally, don’t allow the switching of spells during adventuring, this makes casters (Wizard and Clerics) too flexible and powerful compared to their Warlock and melee class counterparts. Especially, Considering that Warlocks, and eventually Sorcerers, are locked into spells for at minimum an entire level. It creates a lot of imbalance amongst player choices for who is in their party to begin with.
Shadowheart has no dialogue the entirety of the Selunite Temple. This is likely to come later in early access, but in case it’s an oversight. This is possibly only an issue when entering the area from the Goblin Camp, but I haven’t approached from any other angle.
Food is too powerful (the cooked meats more so than others), and potions seem too plentiful or too inexpensive from vendors. If the goal of food is to increase the amount of adventuring the party can do before having to long rest again perhaps adding an additional short rest is a better compromise. The act of eating 15 carrots after a fight does not feel enjoyable or satisfying.
Equipping items during combat should require an action at the very least, maybe having 2 weapon sets for melee characters would be reasonable due to having resistant enemies, but being able to change out weapons from your backpack or change actual worn equipment feels too immersion breaking and cheap.
I haven't finished my current playthrough yet, but wanted to get these ideas out there as I felt the list was getting pretty long. Hopefully people agree with some of the things in here. I can't wait to see what this game can become. Great job so far