This is an in-depth gameplay guide covering differences between the Itch .io and Steam versions of tnmn. Hope this helps.

Game Modes:

Itch: 

• Arcade Mode 
• Nightmare Mode 
• Campaign Mode
• Endless Mode

Steam:
As of the most recent update:

• Mandatory tutorial when you first start 
• Campaign mode 
• Arcade mode 
• Nightmare Mode 
• Custom Mode 
• Card mode

 

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Documents:

Apartment Files:

Itch: 

• Neighbors’ documents have their occupations and bullet points describing their appearances 
• An entry list where you CAN’T cross off the neighbor after letting them enter. 
• You have to open each document one at a time.

Steam:

• Those bullet points were removed / instead has a sticky note for specific features  
• You CAN cross off the neighbors on the entry list after letting them enter.
• IDs, entry requests, and apartment files all can be opened at the same time, which is better to compare the documents side by side.

Entry List:

Check the list to see who you’d expect to come home. Some neighbors may not appear on the list. Being absent from the list does not automatically make them a doppelganger.

Itch:
You CAN’T cross off the neighbor after letting them enter. 

Steam:
You CAN cross off the neighbor on the entry list after letting them in XXXXXXXXX

Identification Card:

The IDs have the same features for both itch and steam, except the ID numbers were shortened on the steam version. 

ID cards consist of the neighbor’s:

• name 
• ID number
• DDD logo
• Picture
• expiration date.

ALWAYS:

• Check for misspellings of the neighbors’ names. 
• Look over every single digit in the ID number.
• Check if the DDD logo is correct and the date is reasonable / not expired.

 

Otherwise, it’s a doppelganger.

If any of those parts has wrong or altered info, it's an automatic doppelganger.

Missing IDs:

A missing ID does not automatically mean the neighbor is a doppelganger. There will always be another discrepancy somewhere else if they are a doppel.

If the neighbor forgets their ID in their apartment, call the apartment.

• If the roommate confirms, allow entry.

If they live alone or nobody is home, but everything else is in order, then allow entry.

Entry Request:

It consists of the neighbor’s:

• Name / 𝓯𝓪𝓬𝓮𝓬𝓪𝓻𝓭
• Apartment number
• Reason for entry

The entry requests are similar for both itch and steam versions, except an APPROVAL STAMP was added into the entry request on Steam.

Itch:
Make sure to check all parts of the entry request if it’s correct. Anything that’s spelled wrong, or information that doesn't match up with the apartment files is a doppelganger.

The neighbors also may forget their entry request in their apartment. It’s pretty much the same process as verifying their IDs.

• If their roommate is there, call them. Once they confirm and everything else is in order, it’s the real neighbor.
• If they have no roommate and documents/appearance are all correct, they are the real person.

 

***The approval stamp DOES NOT exist in this version.

Steam: 

Same mechanics as itch, and an APPROVAL STAMP was added

• Just make sure the approval stamp is also present / looks correct.

  

Checklist: 

Itch:
You CAN use it to help you during your interrogation but isn't mandatory, 

Steam:
SURPRISE now it’s mandatory to fill out. It’s used to grant entry and you will be graded on whether you checked off the right/wrong one during interrogation. 

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Arcade Mode:

You play one workday as a doorman.
On Itch, you’re ranked by letter based on your performance.
On Steam, you're ranked by a score based on your performance. 

Entry:

Itch:

• You can grant entry easily because the open/close door buttons are right in front of you. FREE FOR ALL just kidding.
• During your interrogation, some doppelgangers may be caught red handed and reveal themselves, if you mention something off about their appearance / not on the list.

Steam:

• The open / close door button ONLY appears after you archive your checklist. 
• Denying entry helps with saving the real neighbor from getting killed if you’ve already let in a potential doppelgänger.
• For doppelgangers to be caught red handed, deny them entry instead of immediately calling the DDD (once you know it’s a doppel) and there’s a chance they will reveal themselves.

 

If you suspect you've accidentally let in a doppel, call their apartment after letting them enter. If they don’t answer, then you let in a doppelgänger.

Appearance

“Perfect” doppelgängers only exist if the real person is already upstairs. Other than that, there’s always another flaw. 

Look very closely at their appearances, especially.

• The steam version is harder because some doppels can have very subtle appearances that could be very difficult to catch, so compare documents very closely.
• Usually noses / the placement of their features are very slightly altered and it throws off people the most.

Hats

Itch:
The only characters who can forget their hats at home are Roman and Alf. Anyone else who does not have a hat (and are wearing one in their IDs) are doppelgangers. 

• Roman/Alf will tell you to call up their wives to confirm, but if Lois/Rafttellyn are out, you have to confirm that everything else is in order to verify if it’s the real neighbor.
• Mclooy specifically has his files emphasizing he always wears a hat. If he comes home with no hat, it's a doppel.

Steam:

Unlike the Itch version, ANYONE can legitimately choose not to wear their hat. 

A missing hat alone can possibly mean they’re still the real neighbor. Always verify the documents and appearance first.

In this version, some residents aren't wearing their hats in their photos, like Mclooy.

You can also call up if their roommate is in the apartment to confirm

• If they are not home or do not have a roommate, verify all documents and appearance closely.

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DDD Mechanics

Itch:
You press on the red button first, then call 3312, and the DDD will come and eliminate the doppelganger.

Steam:
You press on the red button and the DDD comes automatically. The feature to dial 3312 turned into an easter egg when you dial it. 

Chester’s Quiz Answers

All versions answers are on the Wiki:
https://thats-not-my-neighbor.fandom.com/wiki/Chester_Titor?so=search

Use the correct quiz answers for the version you are playing cuz theyre all different answers!

Unlikely

Itch:
He comes after your playthrough in Nightmare Mode.

Steam:
He has a separate mode instead of appearing at the end of a nightmare mode run (Card mode). 

Almost like how he is an omnipresent deity that haunts people all across the multiverse.

He also appears in the doorman’s dream after every shift in Campaign Mode. 

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Campaign Mode

For both Itch and Steam:

It’s kind of a story mode where you play one workweek as a doorman. There are different endings where you’ll earn achievements.

Campaign Mode is where you should THOROUGHLY check through everything during your runs if you are going for a specific ending/achievement. If you make a mistake on eliminating a neighbor, you'd likely have to restart the run. 

Endings

Itch

>!Just like Henry: Let in at least 1 doppelgänger during your run !<
>!Model Employee: Complete a full run without letting in any doppelgängers !<
>!Entitled to one call: Kill off all the neighbors no mercy !<
>!6 Feet Under: FREE FOR ALL! LET EVERYBODY IN, ALL ARE WELCOME!! !<
>!Conspiracy Theorist: Eliminate Afton only !<

Steam

>!The endings from Itch turned into Steam achievements, while the “Conspiracy Theorist” ending turned into an Easter egg.!<

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Nightmare Mode

Entry: 

Itch: 

• The entity appears when you kill off a real nightmare. 
• Eliminate two nightmare neighbors and the entity kills off the doorman. 
• The nightmare can forget their documents at home. Call up their roommate and if the roommate confirms, it’s the real them.

Steam: 

• The entity in steam will appear if you kill off the real nightmare tenant. 
• Letting in a doppelganger leads to an automatic death. 
• When it comes to forgetting documents, even if the roommate confirms, the nightmare could potentially still be a doppelganger so check everything else. This part changed from the itch version.

Appearance:

Itch: 

This is a case for comparing the nightmare’s appearance and documents very closely to their respected apartment files. Check every slightest feature.

Some tenants forget their earrings at home: 

• Drugia, anazareth, lilith, yan luo

Their doppelgangers may have missing earrings, too. This is the same process as arcade mode, if their roommate confirms their earrings were left at home, it’s the real nightmare, and grant them entry. 

Steam:
NachoSama made it “easier” to spot doppelgangers as a form of forgiveness since in Nightmare Mode, the player dies easily. 

In the Steam version, sometimes when there is something off with a nightmare’s appearance that’s very hard to catch, there’s also something off with their documents, too. 

VIPs:

In the itch version, the VIPs are special characters that appear in Nightmare Mode and have a small chance of appearing. You don’t have to interrogate them, you easily let them in on nightmare mode. 

VIPs are not in Nightmare Mode on the Steam version. Instead they are part of the wanted doppelganger list (which are basically achievements when you spot them).

Peach Peach 

42

Xuchilbara Lobsel Vith

–In the Itch version, she is known as the nurse. In the Steam version, she changed into a doppelganger for Selenne.

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Custom Mode

Custom Mode was a scrapped idea in the Itch version, then was officially added on the Steam version.

You design up to 24 residents fill up the apartment. The custom assets are only exclusive to arcade mode characters, not nightmare mode. 

You can also create a backup file for your assets of your custom characters if you want to use those models again.

Nacho has been working on an rpg- esque game and here are some updates