These 3 achievements are partially missable:

• Two Hearts Beat as One
  
• In Over Your Head
  
• Bestiary completion

While this is hard to miss, it's missable nonetheless. If you are indecisive or careless during the 5-heart event dialogue for the 5 romance-able partners, you can trigger friendship instead of the romance route. Since you have 5 tries, it's pretty hard to lock yourself out of this achievement completely. Just know that it is possible. Some suggestions:

• Make a backup save once you reach 4 hearts with anyone (optional)
  
• Slow down and read the dialogue carefully during the 5-heart event. Pick any romantically inclined option.

If you feel you already messed up, you have 2 options:

• Start a new save file OR
  
• Use the debug console relationship_kind 1

The debug console solution is definitely not for everyone. However, I still wanted to highlight it as an option because it was mentioned by the developers in one of the support threads.

According to HeraldOfOpera, if you defeat all battlers before attempting this achievement, you may not be able to trigger this achievement. Start a new save file to get a fresh batch of battlers.

This one is not exactly missable, but you can definitely make your life a lot harder if you go out of your way to recycle certain stickers and the Cassette Beasts that come with your partners. For example, the Gear Shear sticker is required to evolve a Velocirifle into Gearyu. Recycling Gear Shear, a sticker found in a cave in Autumn Hills, may result in you having to reroll the sticker shops for hours on end to find a new one. I didn't hit any limits to my stickers and tape storage throughout the course of regular gaming so I advise against casually clearing out your storage.

Head to the Upper Path of Harbourtown. The elevator is near the East Exit. Once on the Upper Path, find a barrel (there are 2 within the vicinity) and bring it to the Northwest house just before a small Northern exit. It may take a few tries, but you can wedge a barrel that will let you jump onto the NW house. Glide from this house to the western fence to reach West Harbourtown. The closest house to your landing spot has an NPC that will gift you a random bootleg. This bootleg is tied to your save file to prevent save scumming (thanks to Lost_Kitty for pointing this out).NOTE: After claiming your freebie, don't forget to go down the stairs within the same area to activate a couple of buttons that permanently link East and West Harbourtown!

Early on you'll get a main objective of collecting 3 rumours. Rumours appear as ? above NPC's heads and usually point to story-related content (such as stations/ranger captains), special encounters (Averevoir, Kuneko, Miss Mimic, etc), or Rogue Fusions/Swarms. Upon successfully following up on a rumour, you'll get On the Grapevine.
While gathering rumours, you'll sometimes come across one regarding a shirtless merchant. This merchant usually has good items such as type-specific tapes, resonance cure, or good stickers so it's worth visiting him before the timer expires.

The following achievements are related to finishing various side content in the game:

On the Hunt: Hoylake is on the upper floor (right side) of Ranger HQ. He'll ask you for help with his research which entails recording various beasts (you can have them pre-recorded):

1. Fanged creature perched on a skull, often spotted in the park: Macabra #028
   
2. Floating worm creature, often spotted in the park: Stardigrade #78
   
3. Winged rabbit, often spotten on Autumn Hill: Thwackalope #51
   
4. Crow with hood and mask, often spotted in the deadlands: Nevermort #47
   
5. Wooden-faced elf, often spotted in the park: Elfless #66

Working Overtime: The NPC by the exit will give you this side quest. Hand over 300 pieces of wood and he will let you pick a design as a reward (+ the achievement).

You can get rare stickers in several ways:

• Randomly stocked by Sticker Vendors
  
• Travelling Merchant
  
• Levelling Up your Cassette Beasts
  
• Recycling your Cassette Beasts
  
• Treasure Chests
  
• Battle Rewards
  
• Time-Limited Letter Box Codes (I got my first rare sticker using LAUNCHDAY)

Think of Bootlegs as elemental variants of a Cassette Beast. There are a total of 14 bootleg types to collect that trigger their respective achievements:


Please note that you can get any of the 14 Bootleg types for free from the NPC in West Harbourtown (mentioned in the section above). The type of bootleg is locked to your save file to discourage save scumming. Additionally, you'll automatically get an Ice-type Bootleg Pombomb as part of Barkley's partner quests: The bootleg Pombomb may no longer be available.
As you progress through the game, you can encounter glitched wild sprites of various beasts which signifies that they are bootlegged versions. Additionally, you can also randomly find them in Rogue Fusions (and their upgraded versions) and Fusion Swarms. Lastly, you can farm a specific bootleg or type using Ritual Candles purchased from Ranger Wilma which work with Fusions. Please refer to this informative Bootleg Monsters and Ritual Candle Guide published by Lost_Kitty for further information: https://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=2969626908
On a somewhat related note, keep in mind that Glitter-type Bootlegs are the rarest of all 14 types. That's because there's no beast that spawns with Glitter as its default typing. When you do see one, exercise caution and prioritize capturing it.

Completing the Bestiary for both Expert Zoologist and Cassette Beasts Master requires:

• Obtaining all 120 species (either by Capturing or Remastering)
  
• Getting all 120 species to 5-star at least once

Please use this link for guidance on obtaining every species.[wiki.cassettebeasts.com]

Also related:

Just as you can fuse, so too can wild enemies. Rogue Fusions appear as overworld anomalies depicted as Black Shadows with horns. They're stronger than the average encounter. You will be farming a TON of these in the post-game to progress your Ranger Board once unlocked.

Fusion Swarms come in 3 waves. The first 2 are groups of regular enemies (a group of 3 and 2) followed by a final wave of a Rogue Fusion plus another regular enemy.
Once you defeat the obvious bad guy that shows up whenever you defeat an Archangel, you'll enter the post-game. At this point, you'll have access to the Ranger Board and be rewarded with the Fusion Radar after the initial Ranger Board Level.
Unlocked at Ranger Board Level 2. Unstable Fusions feature the Cassette Beast Anathema as the other half of the Fusion. Anathema can divide itself and almost always uses Self-Destruct on death so exercise caution if underpowered. They show up as the same Black Shadow as Rogue Fusions, but the Map indicator will label them as Unstable Fusions.
You can encounter Orb Fusions once you hit Ranger Board Level 6. These are typically just stronger layered Fusions. You basically have to break the Orb before it releases the regular Fusion for you to defeat. Orb Fusions have a higher chance of being a Bootleg and typically give more rewards. This will be one of the last few things you complete because it requires hundreds of Fusion Materials collected either by fighting Fusions or copious amounts of questing.

The table below shows the locations for all the Cassette Beasts that are tied to Field Abilities. Averevoir is related to Barkley's Quest. See the ability note below for recording tips.
Story-related (Prologue).
Obtained upon capturing a Bulletino.
Obtained upon capturing a Boltam.
Obtained upon capturing a Diveal.
Obtained upon capturing a Jumpkin. You'll need to use Skelly Jelly (dropped by Jellyton) on some Pumpkins to trigger a battle with a Jumpkin.
Obtained upon capturing an Averevoir. Rather than full-fledged flight, it's more akin to a vertical burst (think OF Flappy Bird) to help you reach greater heights.

Ignore the grey box below. It's related to the seed of your world—a final station that will differ between each save file. The ↓ symbols indicate fast travel stations.

To defeat a ghost, cast New Leaf on it or use the Phase Shift sticker.

Use stickers that activate at the start of a battle. Pre-emptive Strike is the simplest one.
Haunt and Gambit are double-edged stickers that temporarily give you an advantage.
Sometime during the post-game, head back to where you first met Morgante to battle her. She will hit you with Coda Morgana so utilize walls to survive the heavy-hitting attack.

After seeing the credits, head west of Mt. Wirral all the way to the edge of the snowy area. Jump glide West from here into the floating island known as Brokenhead and search for a hooded figure to do battle with Lenna—a Hero of Another Story.

The noticeboard, or "Ranger Board" as I refer to it, is unlocked after dealing with the antagonist of the main story. This event is a clear transition into the post-game and unlocks a series of tasks akin to fetch quests while also mixed in with special events related to achievements. On top of clearing 100 noticeboard quests, there are achievements for completing 5, 20, and 50 quests.

Rather than how many quests, it's more so about how the levels of the Ranger Board you need to reach for various unlocks related to achievements. Here's a small breakdown of these unlocks:

• Level 1 - Fusion Radar
  
• Level 2 - Unstable Fusions
  
• Level 3 - Quest
  
• Level 4 - Bootleg Starter - Thanks to Duslite for confirming this bit of info!
  
• Level 5 - Orb Fusions

Frankie and Vin show up as part of the regular cast in the post-game. They come up periodically as Ranger Board battles and slowly become more seasoned as you keep fighting them.
These 2 achievements are related to completing Level 3 of the Ranger Board. After defeating Helia, you'll get Here Comes the Sun. From that point, head to Harbourtown Station and talk to the Station Attendant. Don't head back to where Morgante was just yet unless you want to have your rematch with her now (see Rebellion). After speaking with the Station Attendant, just go through the conversation/cutscene for The One Who Lies Beneath

There are 6 partners (5 of which you can romance). Getting hearts with these partners unlocks strong upgrades such as the Fusion ability and up to 25% extra strength when fused. I believe most of the partner quests can't be started until you have signed up to become a Ranger.

At some point, Kayleigh will talk about where she used to live (in New Wirall). This will take you to Mourningtown in Autumn Hills which concludes in a battle with the Archangel Mourningstar. This Archangel likes to use ranged moves, a strong Judgement attack, Broadcast, and Walls so it's recommended you bring along a multi-hit attack and Fuse at your earliest convenience to halve Broadcast's efficacy.

Meredith can be spotted just east of the Ranger Outpost. She'll ask you to meet her at her house and from there you'll embark on a short quest to find a specific record that she's looking for. This leads you to Falldown Mall and another simple puzzle involving flipping generator switches and raising platforms to reach the specific store that has the record. This whole sequence leads to a battle with Archangel Nowhere Monarch. This Archangel uses Fire-type attacks and utilizes the hard-hitting Bomb Voyage AoE move at max AP. I recommend bringing Water-type tapes to take advantage of the Healing Steam status effect for supplementary healing. If you have one to spare, try and bring a Pear Fusilli for an instant Fusion Meter charge to re-enter Fusion immediately for either more DPS or to soak damage in anticipation of Bomb Voyage.

Eugene can be located at the Landkeeper Office closest to Harbourtown. After meeting him, clear out the other 4 Landkeeper offices which leads you to the eventual battle with Archangel Mammon. This Archangel likes to cleanse its debuffs, summon Jormungolds for backup, and inflict heavy damage with Market Crash. Stay Fused for the entirety of the fight. Bringing at least one AoE/Splash Damage attack is recommended (Broadcast/Echolocation even better) because Jormungolds will keep getting summoned as the fight goes on.
Sometime after clearing Eugene's quest, you will encounter Sunny at the Gramophone Cafe. Just follow the very simple questline associated with her for the achievement.

We first meet Felix close to his torn-down abode somewhere Northwest of the Ranger Outpost. After the initial meeting, we have to meet him at his home in West Harbourtown. If you don't have access to this place yet, either get the Diveal Swim ability or check the Early West Harbourtown section above. Follow him again on a quest for a strange catgirl encounter. Back at his place, we get introduced to Kuneko for the first time. The next part of the quest has you visiting 4 altars which then leads to a battle against Archangel Shining Kuneko. Bring counters to her Astral-typing (Plastic/Metal) and the battle should just proceed as a simple brawl.

Barkley has the simplest questline out of all the available partners. From his initial location, you just need to climb up using the Jumpkin Vine Ball ability and enter the cave in front of you. Defeat (preferably record) the Averevoir you'll encounter for the Averevoir Flight field ability. If you plan to record this beast, turn off autosave temporarily and save before entering the cave! You can double-record the beast at low HP to boost your chances. Don't use the Aerosol tape because Averevoir will change to Earth when low—use Ceramic/Chrome tape instead.

Viola's questline is relatively short compared to the rest of the available partners. You'll encounter her near one of the campfires in The Marshes. After she saves you, she sets up camp somewhere East of the same area. Head to the beach West (see Ghost on the map below) to get a cutscene with a ghost which prompts you to return to Viola. With Viola in tow, head North of the area where you encountered the ghost to find a shipwreck/station. This station has simple valve-related puzzles which eventually lead to Archangel Robin Goodfellow. It is recommended that you bring various cures, Neutralise, and New Leaf since this boss likes to inflict status effects.

Steam nuked my map. Sorry. If anyone would like to help me re-create it that would be amazing.

Map & Legend

Symbol

Location

Description

Symbol

Location

Description

K

Mourningtown

Kayleigh's Quest

F1

Felix

Initial Location

M1

Meredith

Initial Location

F2

Felix's
House

Where you get
introduced to Kuneko

M2

Meredith's
House

N/A

K1

Elemental
Altar #1

Felix's Quest

M3

Falldown
Mall

Meredith's Quest

K2

Elemental
Altar #2

Felix's Quest

L1(E)

Landkeeper
Office #1

Eugene's
Initial Location

K3

Elemental
Altar #3

Felix's Quest

L2

Landkeeper
Office #2

Eugene's Quest

K4

Elemental
Altar #4

Felix's Quest

L3

Landkeeper
Office #3

Eugene's Quest

B

Barkley

Initial Location

L4

Landkeeper
Office #4

Eugene's Quest

V1

Viola

Initial Encounter

L5

Landkeeper
Office #5

Eugene's Quest

V2

Ghost

Viola's Quest

V3

Titania
Shipwreck

Viola's Quest

Please note that this achievement is potentially missable. Read the note at the start of the guide for more information. I can only speak for Kayleigh when highlighting the romance event since I haven't done those with the other partners. During Kayleigh's 5-heart event, she will play her guitar for you and there will be an opportunity to kiss her. After picking the romance options for this event, keep battling and resting with her to trigger another event (sort of like a hidden 6-heart event) which confirms you are both now in a relationship. This is depicted by a pink-colored dialogue option. The achievement pops up as soon as you select this choice. Note that it does not matter whether you rest at the cafe or a campfire.
Thanks so much to Crayolafish for adding extra clarification regarding this achievement:

引用自 Crayolafish：

For those missing "Two Hearts Beat as One" despite having 5 hearts with a partner and having gone through some romantic dialogue with them -- keep going. You need to have a few more conversations AFTER the 5-heart event, in my experience. Once you two make it past "mutually acknowledging your crushes on each other" and into "properly in love" territory, you should be presented with a pink dialogue choice and you'll have your chance to get the achievement then.

Think of the Stations/Archangels and Ranger Captains as concurrent branches of the story. Eventually they merge back together to allow the player access to the Post-Game content.

After your first battle, you will be asked about your aesthetic—Spooky or Sweet. Think of this as your starter Cassette Beast. Spooky nets you Bansheep while Sweet nets you Candevil. You can get more of these 2 tapes from Ranger Wilma during the post-game.

The LAUNCHDAY code is no longer active. When you get access to the letter box, connect to the internet and enter the code LAUNCHDAY to receive some freebies. The code always gives you a Metal-bootleg Traffikrab and a rare sticker (single use per save). This immediately nets you the following achievements: Monitor the game's socials for future codes.

Huge thanks to Blank for his excellent work and for allowing me to reference his Ranger Captain Guide. Please refer to the following Steam guide to find all of the Ranger Captains and battle them for their respective achievements. At some point, there will be a main quest for rematches. The rematches are optional and are not tied to the achievements below: https://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=2968414707

To reveal this station, look for a rock puzzle just South of a firepit in New Wirral Park. Fill the empty slot with a rock from the vicinity to reveal the entrance. The small dungeon inside is simple and just has a slight objective. Find the Machine Part, use it on the Ticketing Machine, and use it to get a Ticket. The ticket will open the way leading to Archangel Poppetox.

The gimmick for this Archangel is that hitting the effigies summoned will result in your characters taking damage. Poppetox also swaps places with his effigies so you can end up damaging yourself if not paying attention. Thankfully, you can predict when Poppetox will swap places by watching for a spotlight shining down on an effigy. If there is one, Poppetox will swap to that spot so target your attacks accordingly. If it wasn't obvious yet, don't use AoE attacks.
This location is related to the Tiny Dominoth rumour. To reveal this station, find a Magnetic (Blue) Box near an Elemental Altar and haul it south from that location on top of a Magnetic Button. Inside the station, open the normal-sized door using the lever beside it.

This is another simple puzzle where you Eat to grow larger and Drink to shrink your size. Utilize this resizing mechanic to obtain a White Rabbit Key. Return to your default size before using this key on the appropriate chest. This will reveal a lever on the ground. Shrink yourself before using this lever because it will propel you to the start area. Now that you're tiny, you can use the middle entrance to confront Archangel Alice. Alice uses the same resizing mechanics in battle but with the added status buffs and debuffs:

• Eat Me - Size ↑ Attack ↑ Defence ↑ Evasion ↓
  
• Drink Me - Size ↓ Attack ↓ Defence ↓ Evasion ↑

I recommend bringing along Sure-Fire and/or Galactic Beatdown to use whenever she shrinks. When she enlarges herself, I suggest playing defensively. Bring Walls or a combination of Dodge ↑ and Accuracy ↓ in anticipation of her max AP move during her offensive buff state.
Head Southwest of the map towards the Lost Hearts Graveyard. Once you start seeing Crab Statues scattered among gravestones, simply turn all the statues red to reveal the entrance. Once inside, head up once. From this default 2 gravestone position:Archangel Lamento Mori doesn't seem to employ any AoE attacks. Despite this, exercise caution since it still hits hard and has its max AP move by virtue of being an Archangel. This is one of the simpler bosses in the game. One thing to note is that Lamento Mori can revive itself with Ritual.
The first part of this puzzle is very simple. Head down the water stream and drain the water using the lever so you can loot the chests. All the chests trigger a battle. One of these chests will reward you with the Waterloop Key. Use it on the big box to the right of the 3 chests.

Now head East to where the water stream would have ended. There's a room up top that shows the solution to the Crab Statue puzzle just South of this room (back at the entrance). The goal is to match the solution shown on the whiteboard with the Crab Statues (see image below). Doing so opens the gate leading to a battle with Archangel Heckahedron. This Archangel automatically cleanses negative status effects with Neutralise. Additionally, it also uses Damage Roll which can turn very ugly if RNG works against you and it rolls a 20.
This station can be reached by climbing the highest peak of Mt. Wirral. The entrance of the cave you start your ascent at is near a campfire in the snowy area. It's a straightforward path upward once you're in.

In this station, you'll face off with Archangel Babelith. Babelith has a diverse move set containing Plastic, Glass, and Astral moves. Just like the others, Babelith also cleanses negative statuses with Neutralise. Wonderful 7 can wreak all sorts of havoc depending on the resulting effects. As always, I recommend fusing at your earliest convenience. Consider bringing an Astral-type for your Fusion base to gain an AP Boost chemical reaction when hit with Wonderful 7.
Along your quest to complete Morgante's song, you'll have a premature confrontation with Aleph. This results in you getting sent to a faraway place. Thankfully, the ride back home is just a stone's throw away. It's also at this point that you learn about Aleph and your saviour's background.
Before even defeating all the Archangels, you'll have enough verses to complete Morgante's song. At this point, the next objective is to follow the riddle in her song and go to the place(s) it leads you to to perform the necessary action to reveal the final station—Night's Bridge Station. Please note that the final station's location is different for each save file.

Once you've completed Morgante's song (the solution is different for every save file), you can go to the quest menu and replay the full verse at any time to review the clues given. For my save file's seed, it went something like this:

引用自 Morgante：

If you wish to leave this land, then heed my words and hear my song. You must rise to the task at hand, you must walk the path most righteous.

To the East, your wings must fly, to the place only I have known for that is where my chambers lie, halls now empty and alone.

Venture there and head northbound, where your wayward paths shall meet where Auburn trees spring from the ground, their dead leaves crips under your feet.

An altar of fire in this land, atop it is where you must be. At the place you must now stand, run with flames surrounding thee.

Unite this act and this location, to show you the final station.

So with this full verse in mind, my solution was:

• I had to go East
  
• Auburn is reminiscent of Autumn—the season between Summer and Winter.
  • probably Autumn Hill
• Altar of Fire = Elemental Altar in the area
  
• Run with flames surrounding thee = Bulletino Dash
  • atop it is where you must be

And so I dashed over the Elemental Altar to reveal the final station's entrance (for my world).
Not much to say here except that this achievement is for defeating the final boss of the main story. It's very epic and you'll have your friends right by your side! It's ok to be uncertain!
There is no boss related to this achievement. Once you've defeated Aleph, it's just a portal to the end of your journey. Don't worry! You get to save before entering and after viewing the credits, you can reload your game to continue polishing off the rest of the achievements above. Prepare for an emotional journey and some heartfelt music!

Thanks for reading up to this point and showing your support!




Feel free to check out my other 100% guides: https://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=2930315982 https://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=2938224161 https://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=2902500867