Ch.4 · ≈ 2.5 hours
Subterranean — Walkthrough
Stealth-leaning chapter. EMP Launcher unlocked here — swap it in for everything.
Objectives in order
- Pick up the EMP Launcher in the first room — mandatory.
- Solve Puzzle 4-1 (Mirror Grid) for True Ending flag.
- Defeat the Void Acolyte twins.
- Defeat Abyss Walker.
Tips
- EMP cancels phase shifts entirely. Use it on cooldown.
- Crit Chance II synergises with Pulse Visor here — buy it before Abyss Walker.
Boss fight
The chapter ends with Abyss Walker. Weak point: Tail joint (after grapple-pull). Drops: Lunafilament ×5, REM Data: "Hugh-Mirror".
Hacking puzzles in this chapter
- Puzzle 4-1 (Hard) — Mirror Diana's path to unlock the vault.
- Puzzle 4-3 (Hard) — Stabilise the phase pocket to reach a hidden platform.