Tackling the That’s Not My Neighbor 2.1.0 update brings three fresh achievements your way: Nightmare, Nightmare Quiz, and Cosmos. Earning these awards means surviving a surreal alternate mode and nailing some surprisingly obscure trivia. I wasted a bunch of time guessing before tracking down the exact inputs, so this walkthrough saves you the headache.
You will need to trigger a secret phone code, tackle a seven-question exam, and ace Chester’s riddles during standard runs. This guide details every single answer and step required for a clean 100 percent unlock.
Before you begin, make sure you are running the latest game version and have a fresh campaign save ready to go.
Reviewing the quick sequence below will help you knock out all three objectives without missing any missable triggers.
How to Unlock the Nightmare Achievement
The Nightmare achievement sends you into a creepy alternate ruleset just long enough to survive and wake back up. You do not need to finish every single challenge or secure a win in this surreal state.
Follow these steps to trigger the sequence:
- Start Campaign Mode and keep playing until a masked stranger approaches handing out clown leaflets.
- Accept the leaflet directly from him.
- Head to the phone and dial 6666.
- Confirm Yes when the prompt asks if you wish to enter Nightmare Mode.
- Play through the surreal sequence until your character wakes up back in normal Campaign Mode.
The achievement pops immediately upon returning to the standard campaign environment.
How to Unlock the Nightmare Quiz Achievement
Unlocking the Nightmare Quiz achievement requires you to dive into Nightmare Mode and correctly answer seven consecutive trick questions. Because they appear back-to-back, you can finish the entire test in one clean run.
Match your responses against the exact reference list below.
| Detail | Info |
|---|---|
| Question 1 | Psychrolutes Marcidus |
| Question 2 | Chess Boxing |
| Question 3 | Pirates |
| Question 4 | Fawkes |
| Question 5 | Wojtek |
| Question 6 | Zul’Gurub |
| Question 7 | SCP-038 |
Type each entry carefully to avoid spelling errors or rejected inputs. If a multi-word phrase fails to register, try entering it without spaces, such as ChessBoxing instead of Chess Boxing.
How to Unlock the Cosmos Achievement
The Cosmos achievement tests your patience by having you answer six rigorous math and lore questions from Chester during a standard campaign. Once you clear his quiz, he invites you to join him.
I recommend that you deny entry to everyone else so you can focus entirely on Chester’s riddles without getting overwhelmed by regular visitor checks.
Input the exact solutions from the table below.
All Chester Quiz Answers in Campaign Mode
| Detail | Info |
|---|---|
| Question 1 | 42 |
| Question 2 | 302400 |
| Question 3 | 536870912 |
| Question 4 | 38 |
| Question 5 | 45360 |
| Question 6 | 358 |
Finishing all six queries successfully prompts Chester to extend his invitation. Select Yes to secure your Cosmos unlock.