Destructoid has published a guide explaining how players can unlock two optional difficulty modifiers in Mortal Shell 2: Night Mode, which makes the game harder but more rewarding, and Easy Mode, which softens combat for players who want a less punishing experience. Neither is available from the outset, but both can be accessed relatively early once players complete specific in-game tasks, giving fans flexibility over how challenging they want their playthrough to be.

To activate Night Mode, players must obtain the Gloombound Flame item near the Great Arbiter of Flesh mini-boss in Fainweald, then use it to light a brazier at Marrow Keep, where an NPC named Thestus offers to enable the mode; it darkens the environment and toughens enemies in exchange for greater rewards. Easy Mode is unlocked by finding and equipping the Slayer Seal near Marrow Keep, which grants health recovery on successful ripostes, boosted sidearm damage and brief invulnerability — though enabling it disables achievements for that save file.