Astra Hunter Zosma: Astra Hunter Zosma 100% Guide

To preface this, I played on Normal difficulty, so this might not fully apply to higher difficulties.

You stay levelled appropriately to the chapter simply by fighting most enemies once, which also gives you enough currency to keep your equipment up-to-date. No further grinding is required unless you really want to make fights easier for yourself.
You’ll generally only need items when fighting Bosses or while in the Expanding Void, so you may safe them for that unless you absolutely need them. Once you have the Cleric Sigil you will need healing items even less as this Sigil gives you a group healing spell, which can easily be used to regularly top up your health.
The combat strategy I stuck to for almost the entire game is at least one of the basic Sigils you have at the start for gathering SP, the Cleric Sigil for healing and defence and the three elemental Sigils for offence though just one of them suffices if the boss doesn’t have a specific elemental weakness. Add the Astras to that and that’s about all you need for a successful strategy.
Make sure to gather every treasure gem you come across and in the Betwixt check in regularly with the Treasure Hoard for a Rank evaluation as the rewards are quite good and can help you along the way.
I recommend clearing the Expanding Void extra stages as they become accessible unless they really are too troublesome for you at the time. You can find some good equipment in them that are a bit better than what you can get in the shop at that point and defeating the Bosses strengthens your bond with your cat slime which gives you extra points for the cat slime’s abilities and even extra Sigil slots! The special rewards for clearing each stage before continuing the main story are also pretty decent.

All that being said I advice using the remainder of this guide only if you really cannot figure out where a specific treasure is or how to get it. Most if not all of them you should be able to find on your own simply by exploring each area thoroughly. Also remember you can check your treasure notes and found treasure in the menu!

These ended up being my stats (+2 post-game battles):

Treasures in Chapter 1: 3
Treasures in Chapter 2: 5
Treasures in Chapter 3: 5
Treasures in Chapter 4: 5
Treasures in Chapter 5: 6
Treasures in Chapter 6: 6

Treasure 1
In the room where the two slimes jump out of the wall you have to interact with the wall to the left. Then you go left through the secret passage and down to find the treasure.

Treasure 2
In the room just after the first treasure are two prominent music pillars. You have to interact with them in the following order:
Left, Right, Left x3
Or
Left, Right, Left, Left, Right, Left, Left, Right, Left

Treasure 3
In the big room past the long corridor head down right in the middle.

Treasure 4
In the very first room to the left there is a mushroom circle. Stand in the middle of it and repeatedly press the interaction key until you get the treasure.

Treasure 5
At the tall blue mushroom you have to push the green circle block next to it on the right and the red triangle block next to it on the left.
Treasure 6
In the first room after obtaining the ability to use Team-Up Pads and destroy the pale green blocks, there is a light spot of dirt under the ones lined up on a wall. Step on that spot and press the interaction key.
Treasure 7
As the Treasure Note says it is indeed the Mini-Boss infront of you that you need to defeat to get to the treasure.
Tip:Much like most enemies in this area the Mini-Boss is weak to Fire.

Treasure 8
Behind the waterfall to the left before the stairs you have to stand in the middle of it, face upwards and press the interaction key. As Zosma can’t be seen behind the waterfall you might need to try repositioning yourself a few times until you get the spot right.

Treasure 9
This is an uncommon instance where you receive a Treasure Note before coming across the place to use the information in. In the basement with the numerous cells once you have opened them you have to interact with the torches in the cells in the following order of shield colours:
Green, Blue, Red, Green

Treasure 10
Since I actually overlooked the entrance to the hidden room with the corresponding Treasure Note at first, I’ll point it out here.

In the room just before the note there is only one Green Shield. Stand infront of it and then go six tiles down, though you will have to walk around the boxes to do so. Behind the tall box press the interaction key.
Treasure 11
The Bounce Pad in the main area before the yellow treasure chest isn’t working. Step on it once to confirm this, then head outside of the building and talk to the first guard you came across when entering the floor, he will fix it so you can reach the chest.
Treasure 12
You actually get the Treasure Note for this one in the Jump Mad Mini-Boss fight! During the last phase a green bag with a question mark on it shows up and you have to guide the bomb onto it for the note.
As for the actual treasure it is in the room with Apolune, there you have to step on one of the Bounce Pads and head into the room in the back. You have to push the green block onto all four corners of the purple rug once. It looks complicated at first, but is actually quite easy.

Treasure 13
In the last big room of the rafters area there are four yellow buttons. Pressing each of them once and going into the small room above gets you the Treasure Note.
Pressing them twice so they are turned off again will get you the treasure.

Treasure 14
In the Slots area right in the first room there are a couple of rows of slot machines. You have to pull the leaver of a few specific slot machines.

Treasure 15
In the central casino area behind the bar is a secret passageway to a treasure.

Treasure 16
In the Tables area you come across a crossroads where you have to go down into a room with a Team-Up Pad. There you have to destroy only certain blocks to form the image of a heart.
Treasure 17
Close to the end of the chapter on the main path you have to push a few boxes onto specific tiles which the aligning numbers have to add up to each number of the treasure note.

Treasure 18
This one is given to you for free on the main path.

Chapter 4 Casino Quiz Answers
Answer 1: B. Eight
Answer 2: C. 250
Answer 3: A. Green Gambler
Answer 4: B. Restore
Answer 5: A. One
Answer 6: D. The Cooler Crusader isn’t in this game.
Answer 7: B. Bronze Sword
Answer 8: B. Three

Chapter 5 Pub Password
Barnacles

Treasure 19
In the harbour main area starting from the prominent X spot beneath a large fish you need to go 18 steps down and 9 steps to the left and then press the interaction key. Also the treasure is on the water, so you need access to the boat first.
Treasure 20
Located in the first area is a house in which there is a simple box pushing puzzle that awards you the treasure.

Treasure 21
In the harbour the house between the Shop and Save Point holds a treasure but requires a code to enter.
The code is: 3624

Treasure 22
This one requires you to defeat a Mini-Boss again.
Tip:Don’t use offensive spells in this fight as the Treasure Note warns you, so you might want to adjust your Sigils for this one, if you’re currently running a build that is primarily magic

Treasure 23
Before taking the shortcut back to the harbour you have to go down an optional path to the left to get the Arcade Repair Kit from an NPC. Then you have to achieve the high score at the Arcade Machine in the pub. You have to beat five stages in total to beat the game.
Tip:You can somewhat kite the slimes around as they do lock on to you, but don’t follow you exactly.
Treasure 24
In the back of the treasure chamber there is a blue X on the ground. From there go all together 3 steps down and 22 steps to the right, then press the interaction key.

Treasure 25
In the library you have to put the books lying on the ground into the shelves corresponding to the first letter of the last name of the author.
You can brute-force this, but regardless there are the book placements:
Book 1: B
Book 2: T
Book 3: L
Book 4: P

Treasure 26
In the room with the giant cauldron you have to mix a few ingredients together.
Grab 2 bunches of nuts from the jar, 1 cup of milk from the jug and 1 bunch of bananas from the pile. Throw all of them into the cauldron.

Treasure 27
This one is guarded by another Mini-Boss, who outright shows you what he is weak against which changes every round so keep an eye on the sign!

Treasure 28
You have to feed the Black Chest 10000G in total, which you should have if you only bought equipment thus far and didn’t run from any fights. Even if you are short some gold you can just farm some nearby enemies which give around 2500G to 3000G each.

Treasure 29
At the end of the spike room there is another crossroads where you have to go down. There you have to match the right side to the left.
Treasure 30
You need to be Treasure Hunter Rank S to get this treasure. For that you have to collect most though not every single treasure gem if you have already been going through the Expanding Void as well.

Treasures in Phobos: 3
Special Reward: Miracle Drink (Every Stat +)
Treasures in Io: 3
Special Reward: Equipment for Cat Slime
Treasures in Tethys: 3
Special Reward: SP Pendant (SP +)
Treasures in Oberon: 3
Special Reward: Element Charm (All Elements + 10% damage)
Treasures in Proteus: 3
Special Reward: Mini Slots (Random Buff at the start of a battle)
Treasures in Charon: 3
Special Reward: Extra Sigil Slot

Treasure 31
In the first room at the crossroads near the end you have to take the lower path.

Treasure 32
There are three green buttons scattered around the room that you have to step on to build a bridge to get to the treasure.

Treasure 33
You get this one as a reward for defeating the boss.
Tip:Both the balloons and the boss are weak to Electric. Defeating the balloons will get you a few rounds where you can freely attack the boss without him evading three out of four attacks every time. However they do eventually respawn.

Treasure 34
You have to go up in the first room and loop back after crossing the first Team-Up Pad you reach.

Treasure 35
In the third room similarly to the last one you have to loop back after crossing the Team-Up Pad you can reach first.

Treasure 36
Much like in Phobos, you get this one as a reward for defeating the boss.
Tip:The boss is weak to Ice. However when they Conjure Ice this weakness is temporarily mitigated.

Treasure 37
In the second room you have to build a bridge to get to the treasure once more by stepping on two buttons scattered across the room.

Treasure 38
In the last room you have to build a bridge again by activating two buttons. Remember to step on the Team-Up Pad again after you activate the buttons as you won’t be able to leave the room otherwise.

Treasure 39
The pattern of getting the last treasure by defeating the boss of the stage has been fully established with this one.
Tip:If you have the Cleric Sigil equipped you can keep your health topped up and breeze through this fight. Also don’t use Poison! The boss will transfer any poison onto you.

Treasure 40
In the room with the many Jump Pads you have to circle back around after climbing the ledge near the end of the room.

Treasure 41
In the square room the treasure is in the center, you simply have to go back and forth and down the ledges.

Treasure 42
You already know you get this one for defeating the boss.
Tip:The same tactic as for the boss of Tethys applies. With the Cleric Sigil you should be good to go.

Treasure 43
As you can already see when stepping into the room, this is another build-a-bridge treasure!

Treasure 44
You have to use various Jump Pads to get to the Team-Up Pad and loop back around to get the treasure.

Treasure 45
Once again you get the treasure after defeating the boss.
Tip:The same strategy as the last two Expanding Void bosses applies.

Treasure 46
You have to go through the right portals to reach this one. The order is First and then Left.

Treasure 47
Build-a-bridge, but with portals!

Treasure 48
One last Boss to defeat in the Expanding Void!
Tip:They have no particular weakness, just remember you can use each Astra once a fight.

Besides treasures to find there are also achievements to get! You can check them in the Treasure Hoard building in the Betwixt.
This first row is occupied by achievements for completing each chapter.
The second row holds the achievements for defeating the bosses of the Expanding Void. Note that you have to defeat them before continuing the main story to get their achievement!
The third row is where it gets interesting.
The first achievement here is for completing 100 fights.
The second is for reaching Level 25 with Zosma.
The third is for completing the story.
Four through six are for reaching Astra Hunter Rank C, S and SSS, which you get by collecting every treasure bit.
Finally the last achievement of both the second and third row is granted for defeating one extra post-game boss each! The one of the second row is given by defeating the extra boss in the Betwixt on the left and the one of the third row by defeating the extra boss on the right.