Witching Stone

Ok so firstly these are my qualifications (I've gotten a +5 with Ceri but I didn't ss it so you'll just have to trust me)

First thing is with the modifier, the "halved health but heal after every battle" is imo one of the strongest modifiers in the game, and definitely at least a -1 if not stronger, especially since the halved health only applies to the starting health and not the health buffs you get from blessings. Not needing to care about the health you end up with at the end of a battle makes every fight except the final boss like 10x earlier, and bc of the halving not applying to blessings, after factoring in the expected health loss if you didn't have the modifier, you're only missing out on like 5 health most of the time. And this modifier is only gonna get better in future acts.

Secondly, scrying is really not worth the 3 health cost in 3/4 runs, and is definitely not worth 3 acorns if you're using that modifier. I'd recommend reducing the price to 2 life and 1-2 acorns. This might not be necessary depending on later bosses, but there's very few situations in which knowing the boss ahead of time would change whether you win or lose

In terms of starting builds, there are a few that I think need slight buffs for one reason or another:

1. Spark/Water Shield

I know that this is the tutorial build, so it's understandable that it's not doing anything fancy, but I think it just needs a small stat buff. The main problem with it is that because casting both spells requires 5 non-overlapping mana across only 3 colors, it's very difficult to scale it into casting more spells (because like, if you want to add another spell to your arsenal, to cast it you'll have to not cast either spark or water shield, which makes adding spells to your spell book much less of the power spike that it is in other builds. My suggestion for this would be to slightly tweak the stats of spark to make it red/yellow and do 3 damage, putting on the same level as frost shards, but Idk what cost/damage ratio would work both stylistically and in practice so I'd suggest playing around with the numbers. 

2. Catalyst/Magic Dismissal

I love the idea behind this build, but I often find that in practice it just doesn't pan out. I am almost never able to cast more than 1 magic dismissal, and so the damage ends up being incredibly lacking, and this build is often just strictly worse than Ceri's similar bewitch/shiver build. My suggestion would be to replace magic dismissal with double cast, or if you don't want a cooldown spell in the starting build, give magic dismissal a secondary effect like frost 1 to make up for the lackluster dpt.

3. Channel/Crimson Bell

The problem with this build is that after turn 2, the only thing you can do is cast channel for 2 health every other turn and wait which, in addition to being very weak, is also quite boring. Idk if you're willing to put 3 spells in a build, but my first idea would be to add steel bell to the build, giving you things to do until turn 4 and massively speeding up the dpt afterwards. alternatively, you could make channel 3 mana and give it another effect like giving it 1 shield or applying 1 hex or smth, and make a second spell that's 1 mana and makes 1 soul gem without cooldown. Or you could swap the hp and atk of the crimson imp, or smth else that I haven't thought of idk.

And now bc I don't want to come off as a hater, here are my 3 favorite things abt the game (not ordered)

1. The art is genuinely incredible, especially the pixel art

2. The badge system is super neat and allows for a ton of hilariously strong combos

3. The enemies are really well designed and all feel very fair (yet challenging) to fight against 

Holy shit I accidentally wrote an essay. I do want to stress that I think the game rn is really good, and all of these are really just small nitpicks. Hope this wasn't too painful to read lol, and good luck on the game moving forward, I'll definitely be keeping an eye on it!