Addressing Ouroboros' feedback here (from mod comments):
"more skill points you aren't spending to make yourself stronger": This is an odd one to balance, as playing with only 1 character means that global skill points do indeed come slowly and this becomes more concerning... however, playing multiple different characters nets you a TON of global skill points, as the first few levels come quickly (especially if you include modded characters).

A point I want to make is that I really don't like the idea of free xp nodes, as the line between them being too useless or too useful (i.e. a waste of skill points or basically must-gets) feels too thin. I don't like the idea of getting to like level 70 from doing a couple boss rush runs, which the tree makes easier thanks to all the free player power. I do want filling a character's tree to be a longer journey than just one day.

That being said, I believe the current XP curve does become too punishing too early when not using the jewel system, so I will likely make more adjustments to it over time.

"Some of the jewel effects seem antithetical to Isaac's design philosophy": I agree the regen mods are pretty bad, and I've disabled them from rolling in an update I pushed just now.

For the 'tear explosion on death' modifiers, I'm planning to telegraph these before it happens, as a sudden instant unexpected tear explosion does indeed feel unfair sometimes. I'll likely tune their speed as well.

As for the starmight xp gain dropoffs, I'll probably bump the point at which diminishing returns kick in, as 250 might be too low compared to the challenges being presented - maybe upgrade starmight's general xp gain bonus as well.

An addendum: I did introduce an 'XP multiplier' option that you can set with Mod Config Menu, goes from 1 to 3 in jumps of 0.1, in case that helps improve the current mod experience for anyone.

All in all, the Star Tree is meant to be an option to improve the rate at which you progress with characters, at the cost of added challenge, as well as allowing usage of ancient jewels (which are more like challenges for completionism), and not necessarily a must-take. That said, XP curve without using it might need more balancing if it feels way too slow.

Glad to hear what I said was taken into consideration. One thing you mentioned that hadn't occurred to me while I wrote my comments: I am indeed not switching between characters, which is hindering my progress on the global tree which would help give more buffs to balance the jewels out. I wouldn't expect that to be the average players' experience, I already had all completion marks and unlocks in the game so didn't really feel the need to jump around, and under the old skill tree felt I could reasonably max Isaac without dabbling in others, just doing a lot of runs with him in a row, since the global tree didn't have any challenge tied to xp up outside of the one that was based around clearing a room fast, and the one that decreased your starting stats by a pretty minimal amount. I don't think that would be the same for most players -- when I watch two of my friends play Isaac, they hop around between characters every one or two runs.

I also think the changes are good. I'm not against things like enemy death bursts if I can predict them, I just want it to feel fair. The only thing I was totally against was boss regen, and you have removed that. I think the config option for xp multiplier is great too -- it lets people pace themselves as they like.

Thanks for your work.

I've been playing this mod for 3 days straight as I like the sense of rapid progression it offers compared to normal Isaac, and it's been a really good experience and I really enjoyed it. However, I understand that the objective of the skill tree is not to make the player overpowered, but in my case, I am using the maximum amount of gems with the highest possible XP bonus to be able to finish Isaac's tree, it is being very difficult, even though I am relatively new to the game, mobs take a long time to die and bosses even longer, it would be interesting to see some limit on stargems and some positive counterbalance (with blessing gems for example) or stronger stats to accompany the high level of difficulty since the tree It does not strongly affect stats and is more of a help to normal runs. From level 60 onwards I think, the xp gained in an entire run without stargems only goes up one or three levels.

I liked the idea of ​​additional projectiles after the death of mobs, which after getting used to, is easy to dodge and the number of champion mobs didn't seem like much of a bother since they also help with pickups, but their life seems to be the further away from Isaac's reachable damage, especially on the first floors.

That said, this is just my opinion and feedback, I may not be using the stargems in the best way either, but in any case I thank you for your dedication in making this mod, it really is a game changer and I really liked it.

(I made this using google translate so sorry if it had any typos )

Thanks for the feedback - I'll likely be making adjustments to the leveling experience and starmight over the next few days, want to get some personal testing in to see what feels right.

im not going to write for long but i played this mod for a day or two and i really like using it and the whole concept of it. i have a couple notes to put down:

- i did read that the regen mod sucks and they are being seldom removed or something, which is nice i think. with regular enemies and bosses it kinda sucks but with multi segmented things like larry jr, there's a whole lot more regenerated hp per minute so its even worse.

- there are many things to say about the ability to kind of 'farm' exp a lot using certain methods like destroying red poops and more importantly, using the d7 with 9 volt or some other +charge items in a double size room for infinite XP farming. i did use the d7 exploit thing for like 5 minutes before getting bored, but in rooms with a lot of high hp monsters it *might* get kinda ridiculous. you can probably say that its balanced out by being REALLY boring, but i still wanted to mention it because infinite loops in anything should at least be looked at.

- i used the baubleseeker ancient jewel in greed mode and i realised pretty soon that not only are the trinkets in the shop free, you can keep using the reroll machine to spawn even more free trinkets and make the game trivial pretty quickly. this also applies to shops in the standard mode too but its a lot more noticeable and exploitable in greed mode. could probably just be fixed by adding prices to the trinkets found.

that is all i have to say. very great mod and ive been enjoying the jewel system a whole lot. keep it up, ill write down more things if i happen to find anything that raises an eyebrow.

Thanks - I think I'll have d7 disable xp gain on use until entering a new room. I'll also see if I can have the trinkets be sold on the shop instead of plainly replacing items.

i have returned with more notes about balancing:

- you can roll the one-shot protection and debuff cleansing effect on crimson jewels multiple times, then socket many of them at once, letting you have almost free starpower, because those modifiers apparently dont seem to stack or anything.

- using the necronomicon (and potentially other instant kill effects) are stopped by the one-shot protection mod of some crimson jewels. this almost nullifies the item completely, but you could make an argument for why it doesnt necessarily need to be changed. make your own decision about it.

- cursed starpiece challenge can be almost completely nullified if you use baubleseeker alongside it since reverse stars doesn't remove trinkets. it does still remove key pieces and mom's box + the debuff from not having used reversed stars, but it makes the cursed starpiece challenge rewards almost free.

- if you are very powerful and one-shotting rooms frequently, the effects of circadian destructor become almost unnoticeable, such that you dont even notice the card spawning at all. technically this is true with most other ancient jewels, but i noticed this much more with circadian destructor.

- the soul eater challenge and the regenerating HP only really matters in boss fights where the boss is a summoner of many enemies, such as duke of flies and yellow champion gurdy. its never necessarily a softlock because you can just try to avoid killing those spawns since there's a spawn limit for those summons. otherwise, i never noticed soul eater doing much personally.

- some kind of sink for global tree skill points might be desirable? after only a couple days worth of runs, ive practically maxed out the global tree except for the cosmic realignment and shot speed down nodes, and ive got a couple dozen points left over. this might be due in part to the incredible levelling speed from the starcursed jewels. you could still probably add a point sink to the global tree somehow if you felt like that was worth adding in a future update; just putting the idea out there.

im also going to post some bugs i found in that other thread.

Thanks for the feedback. For the one shot protection mod that is kinda the intention, bearing in mind that monsters that survive the one-shot do so with 1 hp.

I'll likely have reverse stars remove a random smelted trinket on use with baubleseeker.

Playing as different characters does indeed net a ton of global points... maybe too many? Especially if you include modded chars. Perhaps there should be some form of limiter? Something like the first 20 or 30 levels don't grant global points except with your highest lvl char.

oh i didnt realise they were set to 1hp, nevermind then, seems good to me. a limiter potentially sounds good, i think with the starjewel update you just level up really really fast especially if you play a bunch of different characters and then you just complete the global tree which is supposed to be like a big effort to fill out. idk, the mod is in beta after all.

Not sure how I feel about the "no xp til 30" for global. It feels a bit counterintuitive. Previously, every level gets you 1 point, which unlocks 1 node. Easy. Now there's a hidden stagger that you will likely encounter pretty early in gameplay, and you won't know why it is happening unless you specifically look at the mod changelog or help menu, so people will likely assume it is a bug.

Assuming I've counted correctly, between the main and starmight trees you'll need a total of 466 global skill points to max both. Take 30 away from that, you're left with 436. There are 17 characters in the game, and 436/17 leaves you with 25.64. That means on average you would have to get every character to level 56 to max your tree. Higher still if you decide to expand the tree any further in updates.

56 isn't incredibly high to begin with, but some people won't play all characters -- I know people who have never touched challenge characters like Blue Baby and Keeper, just because they don't like the idea of them. Others might be missed because the player isn't even aware they exist in the game: How many people organically unlock Lost or Forgotten? Not many.

Without that stagger the average level needed is 28 (466/17=27.41). That's probably too low, instead.

There's probably a lot of ways to handle this, but the few that immediately come to mind would be:
1. Remove the level 30 stagger and just have more total nodes on the global tree
2. Remove the level 30 stagger and have certain nodes on the global tree cost more than 1 (High value nodes and unique ability nodes might cost 2 and 5 points respectively)
2. Remove the level 30 stagger and significantly reduce global nodes, and instead give global points at a larger interval (Say, 1 point whenever a character hits a multiple of 5)
3. Divorce character level and global level entirely. Character level remains as is, and global becomes a second xp bar that fills no matter what character you are playing, so you can pace global xp separately from character xp. (Kinda like Borderlands 3's Guardian Rank system if you've ever played that.)

Don't forget tainted characters and modded characters also have their own xp/levels, so the vanilla character count would be 34 including the former, and I've seen people with a ridiculously large character wheel from all the mods haha.

I don't disagree that it's kinda unintuitive but it was previously quite easy to max the tree without some form of staggering mechanic, if you played more than 1 char.

It's on my to-do to have a changelog pop-up when opening the tree whenever the mod updates, as a few of these updates could've used informing the player about new stuff - it'd have an option to disable this (but starts enabled) if introduced.

I personally actually like the idea of having 2 xp bars, global and per-char, but wonder if it's too 'sudden' or 'jarring' a change to throw in... but I guess that's what betas are for.

Honestly I just figured the mod didn't function with tainted or modded characters since they don't have their own trees. It didn't occur to me to try.

A changelog popup is a great addition. Having to refer to the workshop page rather than having an in-game one is an extra step most people will miss. Changelogs in general are great and I wish more devs included them. (No, Nintendo, "General optimizations" is not a changelog.)

I also think adding that option is great. I generally appreciate anything that lets a user customize the experience, even if it's one I won't personally use.

Personally I think the separate bars would be a great change for the mod as a whole. It'd definitely be jarring, but it seems pretty sensible to me, and would make future development/balancing simpler I suspect. It's a big shift, but ultimately, anything is liable to change in a beta.

Edit: I forgot from earlier, using Haemolacria to denote death bursts is very visible and feels fair. Thanks for the change.

was doing a run as apollyon and got the eraser effect that spawns it in a treasure room, ate it with void. used it again later, and the blue fly/spider spawn effect from the same skill tree activated and killed the thing i was trying to throw the eraser at. this only happened once, but i could see it happening a lot of other times too. a little unfortunate and kinda weird seeing two decent node types on the apollyon tree clash like that, but thats a potential change for another day.

edit: now that i think about it maybe nothing has to be done about it, because using an eraser every 6 rooms and getting that every run is already powerful enough, and void activating lots of effects at once including blue flies and spiders is just what it does.