My goal is to provide detailed instruction so that you can enjoy this wonderful game. Whether you're a completionist or just want to unlock all the props, this guide should have what ever you're looking for. That being said, this guide is incomplete and I'll be updating it as I get more info so be sure to check back if you don't find what you're looking for.

Some notes:

• Turning on snapping (bottom left corner) will really help as proximity is a factor in a lot of unlocks.
  
• If you don't get an unlock or an achievement doesn't pop, try doing the steps in a different order. For example: If you need to place a building next to a tall building you can either place two buildings then make one tall, or place one building, make it tall, then place the other.
  
• There is a timer mechanism in place. If something won't pop you might be doing them too quickly and the game is trying to stop you from spamming.

This guide is to help the completionist. However, the Dev has said that he prefers a sense of mystery in the criteria for unlocking so if you prefer to indulge in that mystery, feel free to dive back into the wonderfully dark vibes of your city and explore naturally.

There's quite a few achievements you get from placing a certain number of items.

The New Employ
Create 50 buildings

The Planner
Create 100 buildings

The Nexus
Create 1000 buildings

Decorator
Place 25 decorations

Billboard Baron
Place 50 decorations

Hologram Queen
Place 500 decorations

This is pretty self-explanatory and simple enough to do. I would avoid just spam adding/removing buildings as I think steam won't track all of them. You're better off just taking your time and making multiple cities.
As far as I am aware, you don't unlock any new items just from placing a certain quantity.

Captain Ahab

Forgot how I got this to pop. Pretty sure it's from LowTown though.

Low Town, High Life
Create a bridge in LowTown

This is probably one of the easiest ones to just stumble on.
All you have to do is place two LowTown buildings next to each other (snapping will really help) and increase their heights. Only certain buildings build bridges at certain heights so just make a bunch and drag them up. Achievement should pop.

SPORTS!

This comes from the New Eden district. Just put a bunch of different New Eden buildings near each other and drag them up.

Corpo Calligraphy
Unlock all building Logos

There are 5 logos to unlock. Unfortunately I've forgotten how to get most of them. A safe bet is to pick Central BD buildings and make them max height. However, I think there might be a sneaky one in LowTown. Will keep an eye out for this one.

1. Omega
   Place an Omega building and drag it up. Omega logo should appear.
   
2. Alpha
   Place an Alpha Building and drag it up. Alpha logo should appear.
   
3. Misc Logo #1
   Place this building from Central BD and drag it as high as you can go.
   

There are other writings you can unlock but I'm not sure if they are required to unlock this achievement.

Sacred Geometry

Place two Omega buildings near each other and make one of them big. Achievement should pop.

Divine Porjection

Place two Alpha buildings near each other and drag one of them up. Achievement should pop.

Hack the Planet
Import an image to the billboard

It's pretty simple. First place a billboard. You should see an option to import or browse.

Then just pick an image. Bear in mind that it won't resize the image to fit so you can get it cut off.

Mood Shift
Use the camera movement tool

This is a pretty long one so stay with me.

1. Open photo mode
   
   
   
   
   
   
   
   
   
   
2. Click this button next to the play icon
   
   
   
   
   
   
   
   
   
   
3. Position your camera where you want to begin, then click "Set position A"
   
   
   
   This message should appear on the center right of your screen
   
   
   
   
   
   
   
4. position your camera where you want it to end, click "Set Position B"
   
   
   
   
   This message should appear on the center right of your screen
   
   
   
   
   
   
   
5. Finally, very important, hit play. Achievement will wait until you hit play.
   

Reach for the Sky

Finally got this to pop. Apparently it's kind of bugged in that it should spawn more easily. Just spam New Eden buildings until it appears. Make sure they're kind of close so the city really builds up.
Alternatively, here's another way that's a little more precise.

Автор сообщения: trungk on Discord

i prok the skyreacher holo by put down one new eden building, upgrade it to the 2nd stage, and put another new eden buiding next to it and upgrade it ( i already build a city ). Hope it help u guys

These unlocks don't have achievements associated with them but they do unlock props so they're still helpful to get.

• Top Helipad
  Place this building from the LowTown district and drag it as high as you can go.
  
• Side Helipad
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  I'm not as sure about this one. Place one of these buildings from Central BD and drag it as high as you can go. It should be one of them.
  
  
• Airship
  Place a bunch of LowTown buildings together. Pretty sure it doesn't matter their height.
  
• Hovercar Highway
  Place this building from the LowTown district and drag it as high as you can go.
  

Like I said, I'll be updating this as I get more info so if you know how to get an achievement or an unlock, please let me know. If you're still having trouble finding something that is on this list, be aware that some buildings don't show up very often which can be the reason some unlocks still aren't popping.

Also, this is my first guide so sorry if the formatting is a little weird. I'm going to try and clean it up in the future. Let me know if this guide helped.

I hope your enjoy your dark vibes!