I have played a modded game on the Master difficulty (keep the difficulty in mind because I won't mention it again when I mention things such as boss health) from start to finish and overall it's an extremely high-quality mod as far as Terraria mods go. The Pyramid was amazing, possibly the best mod biome I've seen, and the occasional secrets are really cool too.
With the I believe there are areas where it can be improved:

I have heard now and then that the bosses are meant to be more powerful than on average, but I believe that even though they are supposed to be stronger they're way too strong. Keep in mind that I have defeated every boss except for the Subspace Serpent.
- Pharaoh's Curse
The beams it launches risks tanking the framerate, it's way too intensive somehow. Any possibility on reducing the impact on performance?
It has way too much health and way too much armor for how early you're supposed to defeat it. At 7500 health on both phases (for a total of 15000, higher than Wall of Flesh) and what I estimate to be about 20-25 armor, which renders high-DPS weapons nearly useless against it. In a way the Pharaoh's Curse shares the Underground Desert curse, which is that it is way too strong to be done earlier on but by the time you are able to reliably do it you already have superior equipment. Fortunately or unfortunately, I had Better Piercing Fix at the time which made the Desert Sand spell book (the one that summons a circle of sand around the player) deal such ludicrous damage that it shredded the Curse. Eventually I uninstalled the mod when I realized that it didn't interact nicely with SoTS weapons and made them ludicrously overpowered.
Overall I believe the health should be reduced to below Wall of Flesh and for the defense to be significantly toned down to make it more doable in pre-hardmode, as even defense reduction items struggle against it.
- The Advisor
It's a hardmode boss disguised as a pre-hardmode boss. I can see the fun in challenging it before hardmode but it also suffers from having over 20000 health and enough armor to make it too tough to significantly damage with pre-hardmode weapons, on top of hostile vertical conditions and having to deal with the Otherworldly Constructs and other teleporting Arboretum enemies beforehand.
- Polaris
Way too spammy with its attacks, but eventually I managed to find a critical flaw in which a Mechanical Minecart can be used to drive away from it while shooting it since it doesn't have any instant horizontal attacks and the Bullet Serpent is not fast enough. It desperately needs fast horizontal attacks, and hopefully less screen spam.
- Lux
I liked the loot from the boss fight but the boss itself was an immense ass-pain to fight. It has an even smaller hit-box than Empress of Light, and the homing laser attack is rather unreliable. I feel it's not the sort of boss you can fight effectively without Soaring Insignia or Rod of Discord.

- Crushers
They're not very effective and their accessories are very weak. For some time after playing the game I didn't even know what a Crusher was because none of the Crushers mention they are Crushers.
- Accessories
There are some accessories that are extremely powerful but the only one that particularly caught my attention as being way too powerful was the accessory that allows you to regenerate health, void and mana with critical hits. With how many critical-boosting items there are in the mod you can consistently heal your entire life bar with a fast-hitting weapon after about 20-30 seconds of shooting with the right accessories. It really has to be nerfed.
- Polarizers
They're a neat concept but it's a bummer that they can't be combined themselves, using Dissolving essences to give some neat moderate buffs to the character is a cool concept but some of Polarizers are just not worthwhile to use as they are, such as the Thermal Polarizer that only increases movement speed (if I recall correctly) and melee attack damage.
- Void armor
I believe the highest-tier armor is the Twilight Assassin armor that you can get out of beating the Advisor, after which there is zero support for void equipment.
- Flashspark Boots
It's rather unwieldy to use with dashes as they sometimes trigger the Flashspark dash and sometimes they don't, and I really hope it gets an option to disable the Flashspark dash because it can be very annoying at times, especially during boss fights that require precise movement.
- Void accessories
They're in a generally good position but the void tablet has no upgrade, which is a bummer because increased void capacity in particular is a really nice element.
- Bulwark item path
The orbiting projectiles are too weak for how advanced the item itself is, they should get some knockback or homing properties.
- Void consumables
I use Magic Storage, but the items that regenerate void aren't categorized as either food or potions, which makes finding them in the UI annoying.
- Pot fabricators
Not only do they produce at double the normal rate (30 seconds instead of 60 as indicated in their chat message) but they also drop anything a normal pot can, including greater health potions and even coin portals. With so many scattered through the Arboretum they're a way too potent source of passive income. The holo-pots should be nerfed.
- Cursed Apple
Is it possible to make it not just repeat the enemy's defeat and only replicate item drop chances? The behavior messes up sometimes and it can lead to things such as two spirits coming out of a construct.


- Obelisk
I didn't know of what it needed at the time because the image was misleading, and I assumed a large diamond would be involved in the process. It would be better if the diamond image was replaced with the shape of the item it actually needs.
- Phase ore
It shows up blank in the Metal Detector. Please fix.
- Economy
Treasure slimes drop way too many coins for how easy they are to defeat. The mod overall has a problem with producing too many coins, constructs drop a lot of coins, treasure slimes drop a lot of coins, the boss loot sells for a lot of coins, I easily ended up with several dozen platinum coins by the end of the run when I normally end up with around 3-4 or even 5.

Overall the mod is amazing and easily beats more "boss-oriented" mods such as Calamity in the fun department, I believe Terraria is way more fun when it's about exploration rather than combat, and this mod is one of the few that really manages to nail that well.