ok ive done all the goals on the ancient starcursed jewels as of now, ive caught up. ill lay out brief thoughts for all of em:

baubleseeker: i think this one would be my favorite jewel out of them all. switching the game from collecting items to collecting trinkets is really cool and satisfies the curiosity of players who wonder what smelting every trinket in the game would look like. power level is about the same as actually collecting items surprisingly, its just a fun twist on the game. of course there are less trinkets than items so it will get old after a bit, but still very fun.

soul watcher: this one is just okay. you really dont feel much difference in regular rooms, and only a limited amount in boss rooms especially if youre overpowered. really the only times this jewel truly matters is when you're up against summoning bosses like gurdy or duke of flies, which are scary. kinda mid otherwise, but at least seeing the super sized bosses from the modifier is really funny.

cursed starpiece: ill admit i cheesed this one with baubleseeker when that combo wasn't fine tuned yet so i dont have much to say. i think if i gave this one a real go id enjoy it, it seems like you kinda get the same amount of items youd get otherwise. it just adds more chaotic interactions to the run for the most part. pretty cool i think.

opalescent purity: kinda also cheesed this one with apollyon but it was still decently difficult and introduced tough choices. i like this one, it does the super hard gameplay thing its trying to do pretty well. it really only sucks when you forget you have it and you pick up like curse of the tower in the curse room and all the other items disappear, but thats more my fault.

umbra: eh i wasnt really feeling it. it sounds okay on paper but not really impactful, you more or less play the same way, just more carefully if you don't get the night light to spawn for a while, not much player choice to do about it. i think ancient jewels are at their best when they add challenging modifiers to the run while still introducing opportunities for player choices to matter.

iridescent purity: this one feels like it was designed to combo with opalescent purity or else you'd kinda have a bad time. i think its slightly worse, it feels like you gotta be careful and also pray to the rng gods at the same time? idk, i was too scared to try it on my own so i just combo'd it with opalescent both times. i might be misinterpreting the raising chance per item you pick up tho, im not 100% sure what it means.

circadian destructor: another good on paper but kinda eh in practice jewel. it sounds really funny, but the tower card doesnt show up nearly enough to truly make it feel like its a real problem, just something that gets in the way every once in a while. also making the enemies invincible to the bombs sucks the fun out a bit, but i can definitely understand the design choice behind that effect getting included.

challenger's starpiece: pretty good jewel, if a little overpowered. this is one of those jewels that looks designed to be threatening, but in practice it only makes your run even more powerful by teleporting you to the boss challenge without having to go down to 1hp. quite strong, but still somewhat fun, i enjoyed my brief time with it.

luminescent die: really interesting jewel and at times, also really funny! everyone sleeps on or even hates the reverse wheel of fortune card, including me, but this challenge kinda shows that it isnt really that bad, it can even benefit you greatly if you get lucky. really, its just the whole item rerolling thing its got going on that scares people. i always used it to see what would happen and i often got a boss reroll out of it, but i didnt mind having my items shuffled either. also being able to repeat floors once in a while was pretty cool. one of my favorites alongside baubleseeker.

gaze averter: this one kinda sucks. im one of those freakshows that actually enjoys tiny planet and my reflection, so i thought this jewel would be super fun, but while playing an actual run i didnt like how it turned out. i think it might be just a skill issue or maybe its so radically different that of course it would suck for the first couple times, but i wasn't really feeling it. i made the choice of selecting lilith to clear it because the incubus familiars kinda lag behind a bit and make it easier to hit enemies while facing away from them. interesting concept but needs fine tuning. i cant imagine the people who HATE those two starting items are having much fun either.

martian ultimatum: i think everyone agrees that mars ♥♥♥♥♥♥♥ sucks but i think this jewel made alright use out of the item. i really like the idea of rings of tears spawning around you and kinda forcing you to use the charge to escape. initially i thought the tears would be much more tightly packed and also spawn closer to me, but they were stupidly easy to just walk away from without having to charge. still though i had to charge away in fights where there were already a ton of tears coming my way. i think this jewel is fine, maybe even one of the better ones.

glace: for some reason i dont remember my runs with this jewel very well, so maybe thats a sign that this challenge didnt really do anything to impact the run. the minus speed and tears kinda sucked but pushing the frozen enemies to spawn circles of tears more than made up for it. i guess the slow build up back to base stats was alright. i dont have strong feelings one way or the other about this jewel, just kinda boring.

chronicler stone: for me, as a player that likes to rush through the game really quick, this jewel did make a small impact, but even then it was really easy to just do a couple more rooms and negate the buff entirely. i think for the types of people that full clear rooms anyways its even more of a sleeper jewel. i do think the concept itself is interesting though, i do think this jewel has potential, but right now its just super weak. maybe if you're already struggling with low hp and are on the later floors like womb where exploring is a net downside, it would matter, but i dont see that happening too often.

saturnian luminite: i like this jewel i think, the idea of a 'melee build' type loadout is cool to me, and i did have a decent amount of fun from trying it. however i did combo this with martian ultimatum, so by using the charge, a decent chunk of the challenge was negated. also, collecting like a single damage item is an easy way to climb out of the initial desperation and back to just having a normal-ish run. despite that though i think this jewel is decent enough. i played before and after it included wings, im not really sure but i think it was slightly better when it didnt have flight, but thats just my personal take.

crimson warpstone: i advocated for this when it was suggested by another user and it was eventually added into the mod. however i think the current implementation of this is really not the best it could be. the all stat down was fine for the most part and you do have to show some knowledge of ultra secret room hunting to get back up to speed, but i was kinda hoping more for a 'use cracked keys everywhere and triple the length of the run' type of deal, personally. i dont think cracked keys spawn enough for me to have the most fun out of it, but i definitely acknowledge that this is just another personal opinion. maybe you can do the whole triple run length thing with red rooms as another jewel sometime, who knows.

sanguinis: this is hands down the most confusing and the most 'just why' jewel out of them all. curse of the cursed as a jewel has potential, but then it just gives you holy mantle and the run is literally like, 95% the same. id argue it even improves the run because you can negate full heart damage from champions using the mantle, and just suffer half a heart of damage instead by passing through a door. i have no idea what you were trying to go for with this genuinely. absolutely not trying to throw shade though, i just want to emphasize that this jewel is just really bizarre.

nullstone: this is really similar to the soul eater jewel; kinda scary in theory but has next to no effect in practice. after playing just a single run or two, you come to realise that most of the first enemies you kill in rooms are usually the weak ones like attack flies and such, just the ones with the least hp that get in the way but don't do much of anything. i was often too powerful in boss fights to even really notice or acknowledge the threat of an extra respawning and cycling enemy in the room. i really like what this gem is trying to go for, but it falls flat when you actually get to experience it ingame. needs more time in the oven, i think this jewel can definitely be one of the higher tier ones with a little more iteration.

--------

there's my thoughts, i think ill play more as more jewels get added, i just wanted to lay down what i thought of them as of now. of course, please remember that im just one guy and i dont think my opinions alone should have HUGE influence over how you go about these jewels. maybe you can change a thing or two here and there, but for large swaths of changes id at least consider waiting for more opinions from different people to roll in? of course you're the developer so you can do as you wish, just trying to be considerate is all. i really didnt truly hate any of the jewels at all and a decent amount were pretty fun actually, so good job on that front.

Oh wow thanks for the in-depth feedback for these - I think I'll make a few adjustments here and there, e.g. for Nullstone I was already thinking it should instead grab the highest hp enemy you kill each room, but I'll probably let the rest sit for a bit until more feedback comes back.

Sanguinis might need a rework though lol, I admit I didn't think it through all that much and was kind of a quick 'what if' of applying curse of the cursed + some sort of mitigation, but this curse is kinda finicky to work with where it's either run-endingly punishing or too easy to mitigate (e.g. with holy mantle); bit of a blurry line to try and find a middle ground in.

I do agree that while crimson warpstone is my favorite conceptually (gee i wonder why), it does feel like keys aren't frequent enough, and there's not much incentive to continue exploring red rooms after you've found tbe ultra secret room
I'd suggest changing the chance for a cracked key to drop for a flat, unchanging chance for keys to replace pickups (ergo requiring you to explore more rooms for those pickups) but idk how feasible or balanced that is on paper

Alternately something that REQUIRES you to explore red rooms (lock the boss door from the outside, replace the trapdoor in error rooms with boss door portal?)

these are some pretty drastic changes though
it might be simpler just to increase the spawn rate of keys (or get rid of the decreasing timer)
and maybe change the ultras secret room reward from completely removing the debuff to just taking a larger chunk off of it

i think itd make sense for liliths bff node to come with a decent damage downgrade rather than a speed downgrade - that way it wouldnt be super busted with the incubus army and rather would benefit more from playing with other familiars still enabled - if it was -50% or -40% damage but your familiar damage was doubled; itd cancel out (or be a minor boost) but make all other familiars you get stronger

i played a bit with the new crimson warpstone jewel and it was definitely an upgrade. there were plenty of cracked keys to go around this time, and i appreciated the fact you could get two at once in the alt path's treasure room. ALSO i really liked how you managed to make them stack like that!! i dont know how hard it was to code that but i was really impressed by it and it made all the difference in the world, with the amount of cracked keys dropping.

it does become much easier to find the ultra secret room as a consequence of the increased drop rate however, but the debuff only halving after finding it is a fine consideration towards that, and now the focus isnt completely on the ultra secret but instead just trying to run around and explore some red rooms to decrease that debuff a little further.

i think its too easy though to hoard red keys and use them all up on the chest/dark room where chest drops have guaranteed items, which happens way more frequently with how this mod likes to give you 10+ luck with all its luck related nodes by the end of the game. still i think that counts as more of an alternative player choice than anything truly gamebreaking. overall an improvement.

just one tidbit, when you buy cracked keys from the shop they just kinda go on the floor and you gotta collect em again, would be nice QoL to also have them get added to the stack right away.

edit: oh also i forgot to briefly mention the nullstone, yes i think the enemies in the boss room are certainly harder than they were before, and are definitely at their strongest on floor 1. i had one monstro fight where the boss itself was trivial to avoid, but the extra enemies had a tendency to chase and shoot projectiles which presented a big problem. however, they are still too weak in the later floors to matter, as before, but i appreciate the change in selecting the highest hp enemy instead. i think you are pushing the needle in the right direction definitely, but you can always push it even further if you deem it necessary.

more than once, while using the nullstone jewel, i have entered the mom's heart boss room and got repositioned to the bottom of the room, which is close to the same point where the nullified enemies started spawning, which gave me contact damage. this probably happens with gurdy to some extent as well. im not sure if it happens all the time but it does happen enough to be a concern.

- sanguinis is able to trigger upon taking any kind of damage, including curse room doors, devil beggars and more, which disrupts the resource management part of the game and doesn't fit with the overall theme of 'be skilled and don't take damage.'

- sanguinis can give you broken hearts on the ascent, including when getting hit, despite having no way to reduce broken hearts with boss rooms. not as egregious, you could leave it in if you wanted to make the ascent extra hard.

okay, ive written a super long 25 page document that is probably way longer than it has to be, and its about basically everything in this mod, just my general thoughts on it all. here's a link to the document.[docs.google.com]
ive done this before, definitely not my first time writing something this long.
also im still just one guy, ect ect, my opinions are not the #1 most important thing in the whole world, wait for other people to come in and share their thoughts. this is more for if you want some small pointers. had fun generally with the whole mod.

Thanks for the xp slider. The leveling is way too fast for my preferences so its nice there is a 0.3 option. TBH I'd love for there to be a 0.03 option.
And fwiw global levels should probably be slower than character levels. What i'm seeing is global levels faster than character levels.

Ideally I'd think global leveling should be about 1/10th the rate of character leveling. It would be great if there were independent options for both character rates and global rates.

But anyway, fantastic mod.

I have some feedback from maxing out the characters from Isaac to Azazel so far:
- Samson's luck mechanic on quick and flawless kills is hilariously broken. Considering there's no time limit on how long you can be on the floor before you can acquire the luck from killing the boss, you can just farm bloody lust and building rage stacks to easily get the luck stacks. It gets to a point where I'm consistently rocking 30+ luck by Womb I. I would significantly reduce the amount of luck Samson gets from bosses and/or enforce a floor-wide time limit for the "quick boss kills" node.
- ??? being able to acquire Hallowed Ground from his passive ability of spawning poop-themed items from using the Poop is way too powerful. The synergy alone can carry him throughout most of the early and mid game. I would remove this item from the pool of poop-themed items he can get from his active Poop item.
- Clarifying how many stat boosts Isaac can get from his Magic Die passive per floor in the node description would help immensely.
- The ability to get a bone heart from Maggy's yum heart passive rarely if ever happens. Maybe increase the chance for it to proc.
Otherwise Cain and Azazel feel pretty balanced and aligned with the philosophy of their original character designs. I'll update further as I max other characters.

Eve also feels balanced, almost forgot about her.

Thanks for the feedback, I'll be checking on these.

I have some feedback and improvements I would personally make for the Cosmic Realignment node in the global skilltree:

First of some feedback about it. The idea of the concept is great. Being able to complete unlocks for character even if you aren't playing them with a downside from the character is just amazing. 22 times 0,06 Luck is Ok as a price for it. However what I don't really enjoy about it is that one can only choose non modded characters, (I dunno if the Siren character is integrated in that, since I don't have that mod). I do understand that it is a compatible thing with other character mods, so I will sleep on that for now. One crucial thing I have to mention still: As far as I know Cosmic Realignment is ONLY for unlocks. This makes it useless if one has all of them already, especially because of the luck downs, and because modded characters don't work it makes it even more pointless.

Personally I would improve the following about it:
It should be possible to allocate at least some modded characters. This doesn't need to happen instantly as there are a lot of them.

For the current time add the following to the Cosmic Realingment:
If you allocate a character, that character will not only get their unlock when completing the checkmarks with another character. The allocated character will also gain the same among of xp and level up coresponding to their level and xp needed to level up. So basically If I play as normal Isaac and I choose to alocate tainted isaac to Cosmic Realignment, both of them gain xp and level up in their respective skill tree. This not only gives Cosmic Realingment a second purpose, but makes it usefull for anyone who already has every unlock for every character. It also makes it easier to level up characters.

(If I am a bit of on some parts please don't complain, instead corect me. I only invested skillpoints in the node once and checked it for like 1-1,5 minutes before I deskilled it, because I didn't want the 22 times 0,06 luck downs and I already had all characters unlocks complete)

That would be all for now.