The Crystal Key — an adventure video game that uses a standard science fiction plot. It tells of embittered alien troops preparing to attack Earth. This order was given personally by Ozgar, a villain who was once defeated by the Arcona race. But no one knows how they did it. The main character plays the role of a skilled pilot who cuts through intergalactic space at the speed of light. He must explore the worlds of that race to find a weapon against the leader of the aliens.

After these events, the actual narrative of The Crystal Key begins. The protagonist discovers portals to other planets, which can be opened with a mysterious crystal key. And this turns out to be exactly what can save humanity from aliens. For the most part, the game is presented in the form of point-and-click scenes, in which you can make a full turn, zoom in on some objects, find objects and use them to solve puzzles. All of them are stored in an inventory of impressive sizes, and they are allowed to be examined at any time. At first, a beginner may find it difficult that the project does not tell about any goals of the hero in a particular location. At the same time, the plot unfolds linearly, which means you need to complete one action so that another one becomes available. But this pays off with obvious riddles that you do not have to puzzle over.