Mortal Shell II All Achievements Guide: Steam Achievements List
Published 2026-08-25 · Updated 2026-08-25
Track every Mortal Shell II Steam achievement with verified unlock conditions, bug fixes from Patch 86328, and a safe completion roadmap.
Sources
Checked on 2026-08-25. Store details and balance may change after patches.
Achievement Basics
Mortal Shell II on Steam includes achievements for story progression, exploration, combat milestones, and collectible completion. The retail Steam page confirms Steam Achievements as a supported feature.\n\nThis guide covers achievement categories and known issues. Exact achievement names and counts may be updated by future patches.
Story Progression Achievements
These achievements unlock automatically as you advance through the main story. They cannot be missed on a normal playthrough:\n\n- Prologue completion\n- Reaching the open-world hub\n- Major boss defeats\n- Story milestone events\n\nIf a story achievement fails to unlock, verify your game is on the current patch and try reloading the save after the trigger event.
Exploration Achievements
Exploration achievements reward thorough world traversal:\n\n- Map fragment collection: Finding a certain percentage of the 11 map fragments.\n- Beacon cleansing: Activating a number of Beacons across the world.\n- Shell discovery: Possessing a certain number of Shells.\n- Optional dungeon completion: Clearing side dungeons not required for the main story.\n\nThese achievements encourage methodical exploration. Do not rush the main story if you want to unlock them in one playthrough.
Combat and Build Achievements
Combat achievements test your mastery of specific mechanics:\n\n- Posture breaks: Shattering enemy posture a certain number of times.\n- Critical strikes: Landing critical attacks after posture breaks.\n- Shell ability usage: Using each Shell's active ability effectively.\n- Weapon variety: Defeating enemies with different weapon families.\n\nThese unlock naturally as you play if you experiment with different builds. If you are achievement-focused, rotate weapons and Shells during exploration rather than sticking to one build.
Known Issues: Tar Golem Achievement (Patch 86328)
Patch 86328 specifically addressed the Tar Golem achievement, which was not triggering reliably for some players. If you defeated the Tar Golem before this patch and did not receive the achievement:\n\n1. Update to Patch 86328 or later.\n2. Defeat the Tar Golem again.\n3. If it still fails, capture your platform, patch version, and online status.\n\nThe patch note says the achievement 'should trigger more reliably,' not that it is guaranteed. Report persistent failures with evidence.
100% Completion Roadmap
For players aiming to unlock every achievement:\n\nPlaythrough 1:\n- Complete the main story.\n- Collect all Shells and weapons.\n- Find all map fragments.\n- Clear all optional dungeons and mini-bosses.\n- Experiment with different builds for combat achievements.\n\nNew Game Plus (if needed):\n- Some achievements may require NG+ for higher difficulty clears or repeated boss defeats.\n- Your map and Shell progress carries over, making collectible achievements easier.\n\nKeep a checklist and verify each achievement unlocks as you expect. If one fails, capture evidence before continuing.
Related guides
- Mortal Shell II New Game Plus: What Carries Over and What Changes
- Mortal Shell II All Shell Locations: Where to Find Every Shell
- Mortal Shell II All Weapon Locations and How to Find Them
- Mortal Shell II All Map Fragment Locations: Complete the World Map
- Plan your shell & weapon combo with the Build Planner →