Simple pointers for locating all the secrets.
TELEPATH – Find 20 secrets.
- The ordinary secrets within the first four episodes are pretty easy to find as long as what to look for. For episodes 1, 2 and 4; the walls leading to the hidden compartments / rooms are marked with a yellow-coloured X symbol at the top. For episode 3, the same-coloured marking can be seen directly on the walls themselves. Interact with the marked walls to reach the goodies within.
Note that the walls leading to the secret areas in the 5th and the final episode are not marked at all and some of them are mandatory for progression. Resort to wall humping as needed.
LEGEND – Find a secret scroll on E1M03.
- E1M03: In the room that houses the red key, open up the hidden compartment at the back corner and interact with the wall to the back to reveal another room that holds the scroll in question.
LIMBO – Сross the level boundary on E2M01.
- E2M01: Open up the first of the two hidden compartments on the path that leads to the red key, destroy the duo of pillars within and interact with the wall behind them to reveal another hidden compartment. Teleport through the window to the snowy landscape outside and keep moving until you step onto the darkness itself.
BLIZZARD – Find a secret portal on E2M03.
- E2M03: After clearing out the final area, instead of stepping into the portal that appears in the middle, return to the start and take the newly-revealed portal to reach the hidden level, E2MXX.
DOPEFISH – Find a Dopefish on E2MXX.
- E2MXX: Coming upon three doors that require three different red keys, take the path on the left and open up the hidden compartment at the corner of the following area. Interact with the wall to the back of the compartment to come across an old friend once more.
TEACHER – Find a secret scroll on E5M01.
- E5M01: In the initial room where you are confronted by two spiders, destroy the pillar at the corner and interact with the wall behind it to reveal a hidden room. After picking up the weapon on offer, turn around and interact with the wall directly in front of you to reveal another room that holds the scroll in question.
INSANE – Find insane difficulty portal in a Hub.
- HUB: Upon returning to the hub after completing the first episode or any of the following episodes (or after finishing the game, for that matter), move towards the portal that selects normal difficulty and shoot the grating that covers the window behind it. Teleport through the window to the room on the other side and step onto the floor plate. Doing so opens up a hidden corridor in the previous room. Teleport back, follow it around and destroy the stained glass to find the teleporter that selects insane difficulty.