Mortal Shell II Achievements

Mortal Shell II features 53 Steam Achievements covering progression milestones, Shell unlocks, weapon and sidearm collection, boss encounters, and special challenges.

Achievement Overview

The 53 achievements in Mortal Shell II are divided into several categories:

• Progression Achievements — Story completion and major milestones
• Shell Achievements — Unlock all eight warrior Shells
• Weapon & Sidearm Achievements — Collect all weapons and sidearms
• Boss Achievements — Defeat major enemies and bosses (many are hidden)
• Collection Achievements — Find all Tarstones, Map Fragments, and Shell Memories
• Upgrade Achievements — Maximize bonding and weapon upgrades
• Challenge Achievements — Complete special objectives and secrets
• Completion Achievement — Unlock all achievements

Key Achievements

Main Completion

• This is Not an Achievement — Complete Mortal Shell II
• No Lifer — Unlock all achievements for Mortal Shell II

Shell Collection

• Shell Seeker — Unlock all eight Shells
• Forever Alone? — Unlock Tiel
• Arrival — Unlock Proxima
• Vengeance is Mine — Unlock Eredrim
• My Brether — Unlock Smert
• Heartless — Unlock Gragu
• Sester — Unlock Sester Genessa (hidden achievement)
• Down with the Thickness — Unlock Lazlo
• The Alchemist — Unlock Sariel

Weapon & Equipment

• Lord of War — Unlock all weapons
• Guns. Lots of Guns — Unlock all sidearms
• Over 9000 — Max out a weapon at the Tarforge
• Decked Out — Reach maximum bonding tier for a Shell at the Shellkeeper

Collectibles

• Stoned — Find all Tarstones
• Sat Nav — Find all Map Fragments
• Seeking the Past — Watch all Shell Memories
• So Fresh, So Clean — Cleanse all Beacons

Hidden Boss Achievements

Several achievements are marked as hidden to avoid spoilers. These primarily involve boss encounters:

• Ultimate Karen — Defeat Magdalena, the Lady of the Woods
• Meat's Back on the Menu, Boys! — Defeat The Lost Child
• Headcase — Defeat The Nameless Captive
• Nightmare Fuel — Defeat Sir Isaac, the Scholar-Prince
• Something in the deep… — Defeat Hexapod
• Praise him! — Defeat The Monolith
• It burnssssssssss — Defeat Droeg, the Conquerer
• Giga Chad — Defeat Malborn Offspring
• Lost Your Head — Defeat Orrem, the Reclaimed
• It's over now? — Defeat Zmey, the Unbidden

Special Challenge Achievements

Some achievements require specific actions or completing optional challenges:

• Peter's Perfect Parry — Perfect Guard each one of The Nameless Captive's headspins using the Untarnished Seal
• No, You Still Can't Win — Take the Tar Golem to his minimum health
• Ascension — Discover the secret of the Mango
• Feed Me — Cause Egon to pass away
• Mid Summer? — Enter the Festival
• Bag Holder — Trigger Baghead's joke ending

Some of these achievements are considered missable and may require specific conditions or timing to complete.

Achievement Restrictions

Difficulty Seals and Achievements

What is the Slayer Seal? The Slayer Seal is an optional item that makes combat significantly easier by restoring health and resolve on Riposte kills and making sidearms deal Break Damage. It's found on a stone throne in the cliffside outer area of Marrow Keep (take the left door from the beacon and continue straight).

Safest completionist approach: collect the items if desired, but do not equip or activate a difficulty-changing option until you have read the warning shown by your current game build.

Evidence boundary: community reports conflict, so this page does not present either outcome as confirmed fact. Last reviewed August 23, 2026.

Missable Achievements

Tutorial-Exclusive Missables

• Mid Summer? — Enter the Festival during the tutorial/opening section. This area becomes inaccessible after leaving the tutorial. Cannot be earned in New Game+.
• No, You Still Can't Win — Take the Tar Golem to his minimum health during the tutorial encounter. This refers to the initial scripted fight with the Tar Golem. Cannot be earned in New Game+.

Can Be Attempted in NG+

• Peter's Perfect Parry — Perfect Guard each one of The Nameless Captive's headspins using the Untarnished Seal. This is a difficult timing-based achievement that can be attempted in New Game+ if missed on the first run. Requires precise parry execution.

Other Important Notes

• Stoned (Find all Tarstones) — Requires entering Night Mode to access all Tarstone locations. Make sure to collect the Temple of Vatra Tarstone before starting New Game+, as some guides report potential issues with this one.
• Seeking the Past (Watch all Shell Memories) — Requires progressing into New Game++ because there are not enough Glimpses in a single playthrough to unlock all 40 Shell Memories. Plan to complete two full playthroughs plus part of New Game++.

Unofficial Sources: KeenGamer Trophy Guide, Steam Community Guides (player content)

Official Steam Achievement Page

For the complete official list with unlock percentages and your personal progress, visit the Steam Community Stats page:

Note: Requires signing in to Steam to view detailed achievement statistics and your personal progress.

Community Achievement Guides

Unofficial player content — not affiliated with Cold Symmetry or Playstack

For detailed walkthroughs and strategies for specific achievements, check out these community resources:

• Steam Community Guides — Player-created achievement guides
• Steam Discussions — Community help for challenging achievements

Related Guides

• Shells Guide — Unlock all eight warrior Shells
• Weapons Guide — Collect all weapons and sidearms
• Bosses Guide — Strategies for boss encounters
• Difficulty Guide — Understanding achievement restrictions
• Progression Guide — Navigate dungeons and find collectibles
• Map Fragments — Find all 11 for Sat Nav
• Beacons & Ova — Track all 49 locations and 46 cleanses