In the first view after the opening movie, take the diary on the floor, where you can find symbols that will be useful all the time.
Walk until you find a giant Cube. Somewhere around you should also find a small rotating Cube: activate it and it will display 4 symbols on the giant Cube.
You need to recreate 4 complete symbols (you can find them in the diary).
(Spoiler: The 4 symbols are Stability on the right/bottom, Observation on the left/bottom, Reception on the left/top, and Rejection on the right/top)
In the 2nd region, walk to the pyramid but you're quickly struck by some flying spheres. You need to deactivate them by entering 2 symbols. You can find the symbols in the environment (one in a 360 view very near, and the other one in the small dome house). Another 360 view contains a clue that will tell you which symbol should be entered at the top, and which one at the bottom.
It should be quite easy with all this information.
(Spoiler: the 2 symbols are Confusion and Vision)
Then you can walk until a train. The commands of the train contain a very challenging puzzle. This puzzle should be solved on your own by rotating the cylinders (using the 3 buttons at the bottom left). It requires a lot of attention and it's difficult.
If this is too much difficult, you can find some good help in the small dome house... Will you find it?
(Spoiler: in the small dome house, you can click on the red vial to play a small animation. The color of the light flashes gives you the order of the buttons to push in the puzzle. The given order (which is not the only one) gives, with O = Orange button, P = Purple and W = White:
Finally is the last puzzle of this region at the top of the pyramid. This one doesn't need any clue, it's a labyrinth. Not very difficult, with a bit of observation and logic. Just be careful that you have to guide 2 spheres (not only the white one!).
You obtain an orb in the inventory.
Go back to Region 1 and walk to the end of the path until the giant Orb. Use the one in your inventory to reach the final region.
Immediately you face a small puzzle with a cube shape. You have to recreate one of the symbols seen in the diary. You should easily guess which one, based on the last text of K'i.
(Spoiler: The latest text in the diary talks of the Terran Mankind. You should have made the link with the symbol People, which is the one to reproduce on the screen)
Here comes the final puzzle! This is the most difficult one. You have to synthesize everything you found before. Make the link between the colors in the diary (small squares on the left), the content of each page that you can link with a symbol (depending on their meaning). Finally try to find a good combination of colors/symbols and enter them in the right order. With a bit of thinking and a piece of paper, you should find the logic behind this.
(Spoiler: The first given color in the center of the device should appear randomly, so it is impossible to give the right answer here. However it is not difficult to solve this puzzle if you have all the elements written on a piece of paper. You need to note down: the symbols with their meaning if you haven't already, give each of them a number, then note the colors of the diary pages with the main word in a capital letter inside. Then draw the puzzle buttons (each 'line' of buttons corresponds to a line of symbols), and give them a number to make it easier. Finally, look at the central color in the puzzle. If it is red for example, then you should refer to the red page of the diary, which gives you the word People. Then look at the symbol named People, which should be number 10. Click on the 10th button of the puzzle to validate your choice. Continue like this until you have successfully pressed the 6 required buttons...)
After that you can click in the final view to discover the ending movie. Congrats!