Puzzle games are no fun when solutions are handed out to you. However, it isn't fun to pace around and accomplish nothing for hours either.

This quick guide and overview will not directly spoil any of the teasing puzzles in the game.

To start off, there are a couple of different zones in the game that are colour coded. These are more or less isolated, making it easy to narrow down the goals.
When you first finish the tutorial, you have access to the red and green zones. In the red zone, your goal is initially to retrieve a gas mask and a wireless module, but there is also a power module that you won't need for now. In the green zone, you can find a green key, night vision goggles, and a remote control for operating wireless modules.

When these items have been acquired, you are ready to enter the yellow zone (gas zone, check the signs) and grab some important items there.
When done, you should have the keys needed to unlock access to a previously locked room, which should be located if you haven't already.

Now you can return to the red zone where the black zone is also located. You are to find some red keys. Two of these keys can be found in the black zone, which you can solve if you have the goggles, a power module, and your trusty wi-fi devices.

Eventually, you will end up with two blue keys, which means that the blue zone is where you want to be. From here, it probably won't be necessary to ever return to the main hub area, and you'll be able to finish the game.