Hi! Great mod, I'm really enjoying it so far! I do have some feedback, however.
1. Nightly Owls are rather annoying in their current state.
Tons of them spawn every night, and despite not being hostile, they follow you around, which just makes accidentally hitting them almost inevitable. Once hit, they turn into a very fast, very damaging enemy that suffers absolutely zero knockback. This is an incredibly big problem for the first few nights when you don't have armour or Hermes Boots, etc. They also tend to cluster around the walls of any house because of their annoying following habit. Also they drop both Nightly Wisps and Terrestrial Boomerangs far too commonly. I just beat Skeletron basically, and I've already gotten hundreds upon hundreds of Nightly Wisps without even trying. The boomerang is also exceptionally powerful considering how early you can get it if you abuse the terrible straight-line AI of the owls to get them stuck.
2. Soaring enemies seem too rare.
Not many players spend much time in the sky especially pre-hardmode, so the extremely low spawnrate that Soaring enemies have is problematic. It means that actually getting Soaring Wisps is not at all worth the time investment compared to other equivalent materials early-game.
3. Undead Hearts are bad. Not their sprite, that's great- but everything else, if I'm being honest.
They spawn in too-high numbers. I sometimes had 3 or 4 on my tail at once without any Water Candles in the area. They're fast, and always go directly toward you with absolutely no course adjustment error like Demon Eyes or Cursed Skulls. Also unlike Cursed Skulls, they don't give any real time to react before ramming you and potentially stunlocking you against a wall because of the dungeon's tight corridors. They have insanely high health given when you'll be encountering them, and take no knockback, making dealing with them in the cramped corridors even more difficult. They're less of a fun interesting enemy and more an annoyance that has made me groan since the first one I came across.
4. The Forest's Army is WAY OP considering when it's supposed to be done. Homing projectiles which are hard to see, a huge hoard of enemies with decent health which all move very fast compared to the other pre-hardmode event, the Goblin Army. The charred trees in particular are insane, making the entire arena bathed in fire, making you take constant damage any time you have to land because of the low Spectre Boots flight time, and then you get stunlocked momentarily and the homing projectiles have a chance to hit you, etc. I survived on average 10-15 seconds and had to respawn like 6 times before Magnoliac even spawned, and then it had two phases, unexpectedly. A tad overkill for the second event.
5. One minor incompatability- the Firestorm in a bottle seems to fix your jump height completely. When using, for example, the Crouch/Crawl/Roll Mod's crouching jump, I gain no extra height if I have the Firestorm in a Bottle equipped.
Note: According to the dev, the crouch jump increases jump speed like frog legs, instead of jump height like the balloons. If that can help to solve the issue that'd be nice.
6. Are the Trash Man and Pyromaniac really all that necessary? I feel like the Pyromaniac's wares could easily go into the Demolitionist's inventory, and the Trash Man is... a meme who sells mostly useless (literal) garbage. Mainly the Trash Man.
Why. I need to make houses for all these NPCs. I have yet to check but if there's a config option to disable him that would be great. Terraria has enough immersion-breaking things, it doesn't need an explicitly obvious Danny DeVito playing an actual Danny DeVito character.
What does the firestorm in a bottle do
It enhances your first jump. Unlike other "* in a Bottle" accessories, it just increases the height and greatly increases horizontal speed of your singular normal jump. It also releases a firey blast on jump that knockbacks and deals minimal damage to enemies even through walls. Quite useful overall, though the price is hefty for when it would be useful.