I've finished build v1.11 and enjoyed it.
My advice is:
As I mentioned in the Discord, the Shadowbolts fight is good except if you have Rainbow in your party and have her throw out Hurricanes every turn you defeat the Shadowbolts in about 2-3 turns. Even if the Shadowbolts were changed to fight Rainbow with highest priority I am guessing the other 3 party members could throw healing potions at Rainbow to counterbalance that. I suggest the Shadowbolts could on their first turn each cast the Shield spell on themselves if they see Rainbow and that might protect them from Hurricane for five turns, so long as after that the Shadowbolts use the other interesting spells like Dark Blessing, etc. I wonder what would happen if every Shadowbolts member decided to do Hurricane on the first or second turn I think that would be too hard. So yeah there is a way to make the fight too easy and a way to make the fight too hard so there is a balance in there somewhere.
I think the Dragon shopkeeper in the volcano should sell Rarity a better or at least different gem, because her Emerald is really bad at fighting fire creatures in the volcano. Maybe there could even be a selection of all damage types of gems from the Dragon because he is a Dragon after all he eats gems.
Does Rarity ever get the ability Diamond Shower that I saw the Changelings use when they were morphed as Rarity? I am in the Canterlot Gem Caves with Rarity at Level 31 and she still only has Gemshot.
Why is Remedy only sold at Sugarcube corner? The shops at the changeling hive and the volcano don't sell Remedy. This is OK because I had enough money to buy as many Remedy as I wanted at Sugarcube corner but if I hadn't I would have been upset I couldn't later. Maybe Mrs. Cake could say Remedys are an item you can't find anywhere else?
I only did a few minutes of grinding (less than 30 minutes total?) and I got enough money to buy the best armor and weapons for everyone (not just the 4 current party members) every time there was a better set of armor and weapons and by the gem caves I had 30 Cupcakes, 50 Soda, 20 Tonic, 20 Remedy, and 20 Tents. This is OK because there is no shopkeeper in the gem caves so this has to last two levels (volcano and gem caves) not one (and who knows maybe future content (the final level) might not have a shopkeeper either). I think I got this much money so fast because I wasn't scared to do special attacks (that cost mana) and lose hitpoints on my party members because both are refilled upon level up. I used almost no items not even tents (I used like 4 tents in total the entire game) by doing this and also learning how many hitpoints enemies have (so I don't waste special attacks on almost dead enemies and if the enemies are really weak they can be taken out by 4 basic attacks one from each party member in that turn) and which enemies need to be defeated first because they are more dangerous. I prefer minimal grinding actually but I think the boss fights should be much harder and use about 10 mana potions and a few health potions or whatever each time, because boss fights should be hard and if they are too hard just grind a few minutes to get a few hundred bits to buy more consumable items.
The boss fights are too easy if you have enough Soda (I got 50 near the end) and throw out special attacks all the time fueled by Soda. Especially if you know whether or not the boss has status effect attacks, so you should bring in Fluttershy and equip her with the accessory that prevents all status conditions so she can Remedy party members. I love that accessory I think it should exist but I think boss fights should be harder and require more consumables. Mana potions are so important and so cheap maybe each boss fight should require about 10 mana potions to get through. I am also wondering whether it was easier for me I always had Luna and Celestia in the party when there is a boss fight because they both have high damage attacks (Moonbeam and Sunlight) and resistance to Dark (their accessories).
I think Twilight's shield spell is good but I think there should be a boss fight where it really shines. Maybe the Umbra fight or future Sombra fight? Umbra could do a lot more damage and Twilight would have to shield. I managed to defeat Umbra so fast I didn't even need to use more than about 3 or 4 first aids and no cupcakes (I don't remember how many sodas). I am not sure how strong Umbra actually is she seemed to have the same attacks as Luna (that Dark area of effect special attack, that Dark single target special attack, and that stun or whatever) but when she casts Dark Blessing that one time she gains a LOT of health but then loses health automatically every turn after that as a side-effect. I think Umbra should be stronger than just a stronger Dark Blessing because she mastered the darkness for years. I suggest all of her different attacks should have a chance (or more of a chance) to have a negative status effect (lore reason: because she is better at dark corruption magic than Nightmare Moon), making her Dark area of effect attack more powerful than Luna's, and because of that Umbra's special attack that does a status effect should be more powerful to balance it against her now more powerful other attacks.
I am excited to see what the Dark Gem could be good for. It heals Umbra during the boss fight so obviously the Dark Gem is intended to be useful in the Sombra level afterwards.