Despite what this game's reputation may have you believe, getting all achievements in Genius of Sappheiros is surprisingly simple. You only need to do one playthrough, and nothing is actually missable. There's no bizarrely complicated quest chains spanning the whole game, nor is any of the bonus content particularly hidden away. You're not even required to play on any specific difficulty for anything. You just gotta be willing to push through everything this game has to offer and contend with some tedious grinding to cap it all off.

If you manage to obtain every achievement, you'll get the final one as a capstone to your efforts:

Touhou Souzinengi V Completionist
Obtain all other achievements



Note: Thank you to ZeldaFan024 for providing the exact rooms each enemy can be found in. You can check out their guide on that here: https://steamproxy.net/sharedfiles/filedetails/?id=3038934024

The following achievements are obtained as a part of natural progression through the story. Each one will be tagged to avoid spoilers.

People's Warm Welcome
Story Progress: Defeat China


Vampire Killer
Story Progress: Defeat Remi & Nitori


Alice Game
Story Progress: Defeat Alice


Handy Item GET!
Story Progress: Defeat Satori


Ghost Hunter
Story Progress: Defeat Youmu & Yuyuko


Kyan!
Story Progress: Defeat Komachi


Hero of the Sunflower Fields
Story Progress: Defeat Medicine & Yuuka


Eientei Invader
Story Progress: Defeat Udonge & Tewi


Help Me, Eirin!
Story Progress: Defeat Eirin & Kaguya


Godslayer
Story Progress: Defeat Suwako & Kanako


Girl of the Sphere of Neither Perception nor Non-Perception
Story Progress: Defeat Tenshi


Let's Start by Taking Down That Turtle
Story Progress: Defeat Genjii


Lakebed Temple Gatekeeper
Story Progress: Defeat Genjii and Matsuba


She Was the Weakest Among the Three Servants
Story Progress: Defeat the Three Servants


Alligator Goddess Anastasis
Story Progress: Defeat Anastasis


Turtle Goddess Biotopos
Story Progress: Defeat Biotopos


Snake Goddess Litos
Story Progress: Defeat Litos


Green Sea God Incident
Story Progress: Defeat the final story boss


Hinamatsuri
Story Progress: Defeat Hina


The One Who Conquers the Dark World
Story Progress: Defeat That Which Detests All


Resentment Incident
Story Progress: Resolve the Resentment Incident

W-What Are You Doing!?
Have Alice kick a dog enemy


Just have Alice use a normal attack with her Legguards equipped on one of the following enemies:

• Hellhound
  
• Cerberus
  
• Orthrus
  
• Bloodhound

I'm unsure if the Shiisaa, King Shiisaa, or Metal Shiisaa count towards this achievement.

Kappa Science is the Best in the World!
Defeat any type of Yukkuri with Nitori's Last Word


If you don't manage to get this achievement naturally by the time you're done, put Akyuu and Nitori in your party. Once you find a Yukkuri, have Akyuu cast Damage Net (which she can get by defeating a few different Aquatic enemies herself) to prevent it from escaping, then whittle it down to low HP. Once it's low enough, have your own party drop Nitori to low HP and hope her Last Word activates. If you get it ready, cast it on the Yukkuri to finish the job and unlock the achievement.

That's Enough, Yuugi!
Defeat an insect enemy during Berserker Soul


This one is simple enough. Just have Yuugi cast Berserker Soul, then defeat any Insect enemy with a normal attack.

Exterminator
Defeat the Terminator


The Terminator is a rare spawning midboss found in room E of the Depths of Resentment that can easily be beaten with the same strats used for its stronger quest boss variant: just outspeed it and debuff its PAtk and Acc to render it completely toothless.

Note: It is not to be confused with the Terminator MKII fought in the quest "Seeking Terminator". As far as I'm aware, this achievement only activates when the original Terminator is defeated.

Squid Poacher
Defeat over 100 Mental Flayer-type enemies


The following enemies count for this achievement:

• Mental Flayer
  
• Elite Mental Flayer
  
• Petit Flayer
  
• Ika Daemon
  
• Queen Flayer
  
• Mental Flayer Lord
  
• Empress Flayer
  
• Veteran Flayer
  
• King Flayer

Don't Lose Hope!
Have your first game over


Not getting this achievement is honestly more impressive than getting all achievements.

Shrine Maiden of Paradise
Reach level 70


Shrine Maiden of Eternity
Reach level 99


First things first, to increase the level cap from level 70 to level 99, you'll need to clear the quest "Pierce the Heavens! Scarlet Pachon", which I go more in-depth on here:

Break the Limits! A Guide to Surpassing Lv 70 and Pow Lv 99 

A Guide for 東方蒼神縁起V -The genius of sappheiros-

By: Gloochi

An in-depth guide to the Library Depths and Myouren Temple Depths, a pair of bonus dungeons added into the Souzinengi V release of the game.

From there, you can boost EXP gain with the following methods:

• Litos' Commander Power - +2% Party EXP
  
• 16 pts in Akyuu's Omen skill tree - +25% EXP and +15% Party EXP
  
• Defeat all Unknown enemies w/ Akyuu - +6% Party EXP
  
• Rabbit's Foot - +1% Party EXP
  
• Shoes of Happiness - +3% Party EXP
  
• Hat of Happiness - +5% Party EXP
  
• Bloomers of Happiness - +10% Party EXP
  
• Giant Medal of Good Fortune - +20% Party EXP
  
• Yukkuri Medal - +10% EXP
  
• Yukkuri Crest - +20% EXP
  
• Yukkuri Crown - +30% EXP
  
• Yukkuri Title - +100% EXP

If Akyuu doesn't reach level 99 before you get all other achievements, the quests "The Scarlet Devil Mansion Burns Again" and "Counterattack on Titans" are particularly lucrative for EXP.


You're Enjoying This Game, Aren't You!?
Surpass 100 hours of playtime


Seasoned Warrior
Defeat 5000 monsters


Extreme Damage Dealer
Deal over 10000 damage


All three of these achievements should be achieved naturally well before getting all other achievements.

The Birth of the Ultimate Goddess Lifeform!
Story Progress: Defeat the final story boss's perfect form


During the final boss, if you allow the Three Sisters to chant three times, the phase will end immediately and cut straight to the Three Goddesses phase. However, their stats will be massively buffed, their species will change from Deity to Unknown, and they'll get four actions per turn. For comparison:
You can rematch the final boss at any time, so don't worry about trying to do this during the endgame. Instead, you should come back around the time you're ready to face the Resentment Incident at the earliest. Make sure your second party is well equipped with high level Dragon Scales, Garter Belts, the Kagami and Magatama, and various other elemental resist equipment, and then use the same strats you would normally use to defeat the Three Goddesses.


Dojoyaburi
Defeat Trailokyavijaya


Strong Fighter
Defeat the Elder Dragon


Trailokyavijaya and the Elder Dragon are fought in the 8 star quests "Asura, You Sure That's Enough of a Dojo?" and "Quest for Tiny Babies" respectively. For more in-depth detail on these fights, check this guide:

Odd Jobs of Gensokyo ~ A Complete Guide to the Optional Side Quests 

A Guide for 東方蒼神縁起V -The genius of sappheiros-

By: Gloochi

A guide to the 53 optional sidequests available throughout and after completing Lingering Summer Heat, including how to unlock them, strategies for clearing them, and all their rewards.

Great Emperor
Defeat the Demiurge NEO


Archangel Killer
Defeat the Archangel


The Demiurge NEO and the Archangel are fought in the 8 star quests "Pierce the Heavens! Scarlet Pachon" and "Path to Power" respectively. For more in-depth detail on these fights, check this guide:

Break the Limits! A Guide to Surpassing Lv 70 and Pow Lv 99 

A Guide for 東方蒼神縁起V -The genius of sappheiros-

By: Gloochi

An in-depth guide to the Library Depths and Myouren Temple Depths, a pair of bonus dungeons added into the Souzinengi V release of the game.

The One Who Clears All
Story Progress: Clear all quests


Hilariously enough, despite featuring Chaos in the achievement icon, it's impossible to unlock this achievement by defeating Chaos. All you need to do is complete all 18 story quests and all 53 optional quests. For more in-depth info on the optional quests, check this guide:

Odd Jobs of Gensokyo ~ A Complete Guide to the Optional Side Quests 

A Guide for 東方蒼神縁起V -The genius of sappheiros-

By: Gloochi

A guide to the 53 optional sidequests available throughout and after completing Lingering Summer Heat, including how to unlock them, strategies for clearing them, and all their rewards.

Master of Kourindou
Obtain all items


All you need to do is obtain all items in the game at least once. You don't need to own them all at once (which is impossible, due to some being used in synthesis and not being reobtainable), just own each one at some point. By examining the book in Kourindou, you can check a list of all items in the game, where to obtain them, and whether or not you've had them before.
Note: Due to an oversight, the following items are not included in the item list and may not be necessary for this achievement:

• Amulet of Haborym
  
• Amulet of Forneus
  
• Amulet of Alloces
  
• Amulet of Bune
  
• Amulet of Amaterasu
  
• Amulet of Tsukuyomi

Each of these items can be synthesized after progressing far enough in the game.

Bunbunmaru Newspaper... Complete!
Defeat all non-boss monsters


All normal enemies need to be defeated and registered in the compendium, though you don't have to use Aya's Perceive skill on them. The following enemies are particularly hard to find if you don't know where to look:

• Officer Daemon (Red) - Genbu Ravine room D and Genbu Lake C
  
• Dominion - Genbu Ravine room G and Genbu Lake F
  
• Greater Daemon - Lakebed Temple (Team 1) roomsF and H, Inner Lakebed Temple room K, and Grand Temple room J
  
• Hydra - Grand Temple rooms P, Q, and R
  
• Marisahedron - Gorgon Sanctuary room A
  
• Daemonsider - Gorgon Sanctuary room A
  
• Capricorn - Gorgon Sanctuary room B
  
• Bodaiju - Gorgon Sanctuary room B
  
• Druid - Gorgon Sanctuary room C
  
• Pendragon - Gorgon Sanctuary room C
  
• Hekatoncheir - Gorgon Sanctuary room D
  
• Ambivalenz - Gorgon Sanctuary room D
  
• Two-Headed Dragon - Gorgon Sanctuary room E
  
• Lightning Baron - Gorgon Sanctuary room E
  
• Crom Cruach - Gorgon Sanctuary room F
  
• Yukkuri King - Many locations but most easily in Gorgon Sanctuary room F and Hieda Manor Basement B3F rooms B and C
  
• Rare Beetle - Gorgon Sanctuary rooms B, C, D, E, F (incredibly rare)
  
• All Incident Level 1-4 enemies - Underground
  
• Dragon Pansee - Depths of Resentment room B
  
• Asura - Depths of Resentment room C
  
• Demiurge - Depths of Resentment room D
  
• Garuda - Depths of Resentment rooms D and E
  
• Terminator - Depths of Resentment room E
  
• Amukihajah - Depths of Resentment room F
  
• Shofet - Depths of Resentment room G
  
• Atomic Monster - Depths of Resentment room H
  
• Angelsider - Depths of Resentment room I
  
• Royal Duke - Depths of Resentment room J
  
• Seraphim - Depths of Resentment room K
  
• Dragon Eater - Depths of Resentment room K
  
• Dragon - Depths of Resentment room L
  
• Yukkuri Emperor - Many locations but most easily in Depths of Resentment room L
  
• Glory Empress - Barrier Distortion room H
  
• Resentful Shofet - Barrier Distortion rooms I and P
  
• Terminator Custom - Barrier Distortion rooms L, M, and R
  
• Cernnunos - Barrier Distortion rooms N, O, and P
  
• Paradox - Barrier Distortion rooms N and O
  
• Mac Lir - Barrier Distortion rooms L, M, N, O, and P
  
• Mordred - Barrier Distortion rooms L, M, N, O, and P
  
• Allocer - Barrier Distortion room P
  
• Elite Two-Headed Dragon - Barrier Distortion rooms J and P
  
• Malicehedron - Barrier Distortion rooms E, F, and P
  
• Nehasim Seraphim - Barrier Distortion rooms K and R
  
• Bune - Barrier Distortion room R
  
• Haborym - Barrier Distortion room R
  
• Forneus - Barrier Distortion room R
  
• Chiyou - Barrier Distortion rooms N and R
  
• Three-Star General - Barrier Distortion rooms P and R
  
• Dragonlord - Barrier Distortion rooms O and R
  
• Yuckuri - Library Depths room B and Temple Depths room B ; Potentially summoned by Remilia's Last Word
  
• Yuckuri Sisters - Hieda Manor Basement B3F rooms B and C, Library Depths room C, and Temple Depths room C ; Potentially summoned by Remilia's Last Word
  
• Stray Yuckuri - Library Depths room D, Temple Depths room D, Deepest Depths of Resentment room G, and Barrier Distortion room H ; Potentially summoned by Remilia's Last Word
  
• Yuckuri King - Library Depths room C, Temple Depths room C, Deepest Depths of Resentment rooms D and H ; Potentially summoned by Remilia's Last Word
  
• Reimu Emperor - Depths of Resentment room L, Library Depths room D, Temple Depths room D, Deepest Depths of Resentment rooms I, J, and K, Barrier Distortion rooms E and F ; Potentially summoned by Remilia's Last Word

Your Skills Are Mine...
Obtain all of Satori's learnable skills


For more in-depth info on Satori's learnable skills and how to get them, check this guide:

How To Train Your Satori ~ Building the Perfect Knockoff Blue Mage 

A Guide for 東方蒼神縁起V -The genius of sappheiros-

By: Gloochi

A complete guide to obtaining all 142 of Satori's learnable skills and spells and how to build her into a formidable party member.

Treasure Hunter
Open all treasure chests


This achievement should pop after opening all 658 treasure chests and reaching 100% Chest Collection Rate. Any missed chests will be marked in the compendium after beating that dungeon's boss.
However, the locations of the 10 silver keys will not be marked. They can be found here:

• Great Library room C
  
• Scarlet Devil Mansion room G
  
• Scarlet Devil Mansion room K
  
• Palace of the Earth Spirits room E
  
• Palace of the Earth Spirits room K
  
• Netherworld room J
  
• Netherworld room E via a teleporter in Serpent Way room A
  
• Youkai Mountain room G
  
• Sea of Mysterious Clouds room I
  
• Forest of Magic 2 room H
  

Skilled Commander
Obtain all formations


For more in-depth info on formations and where to get them, check this guide:

Formations and You ~ Strategizing Your Way Through Gensokyo 

A Guide for 東方蒼神縁起V -The genius of sappheiros-

By: Gloochi

A guide to the 60 formations available in this game, listing their effects and where to obtain them.

Hakurei Synthesist
Create all equipment available through synthesis


For more in-depth info on synthesis and material grinding, check this guide:

The Wonders of Synthesis ~ The Woes of Grinding 

A Guide for 東方蒼神縁起V -The genius of sappheiros-

By: Gloochi

An in-depth guide to synthesizing every item available at Korindou and where to grind for the necessary materials.