Introduction
For anyone wondering why I am making this guide. Players can and will find a way to solo play this game. I am just going to make it as easy as possible. However I HIGHLY suggest players should play this game with a friend. But not everyone will be able to do so.
For those that can or are willing to play this game with someone else. I would suggest going to the Rusty Lake Discord group. As there are plenty of fans of the series who would happily play with you. But for those who won't or can't here is how to solo play this game by yourself. But be prepared that you are robbing yourself of the intended experience for playing this game.
Step 1: Buy One Copy Of The Game.
You only need one copy of this game to make this work. So buy the steam version of this game and download it. Run the steam version of the game and when it is running click on the gear icon in the top right.
In the settings menu you will need to turn off "Fullscreen mode".
Step 2: Setting Up The Second Windowed Version Of The Game.
Now go back to your Steam library and right click on the game "The Past Within" in the drop down menu click on Properties.
In the new window click the tab "local files" in the left hand menu and then the button "Browse" in the top right.
This should open up the games local directory window. Here you can click on the game "The Past Within" to open up the second window of this game.
Step 3: Just Play The Game On Two Windows.
On one window make sure to play as the past and the other window play as the future. Also make sure to pick the same puzzle setting (Butterfly or Bee) on both windows.
When playing the game on one window the other will be paused. So timed puzzles will be easier to do.
Hope this guide helps. But again. I would prefer it if you never had to use it.
Source: https://steamcommunity.com/sharedfiles/filedetails/?id=2883436430