The game is set approximately a century in the future, when small scientific bases have been settled on Mars. When an earthquake occurs and traps one scientist below ground, he is forced to explore what turns out to be an immense system of ancient caverns filled with martian 'zoa'. The plot unfolds through the player's actions & discoveries, and converations with another researcher safe in the base and an AI assistant. Levels can be solved in many different ways, there are additional optional sidequests that add backstory or provide more abilities, and there are multiple endings to the game.
The player is tasked with researching the various types of alien organisms present in the caverns, and their behavior, reproduction and effects among other things. Each individual cavern has a biomass level, corresponding to a rating from one star to five. Higher ratings are more difficult to achieve, but may activate certain other events. Many caverns, as well as smaller sections in caverns are sealed off by impassable barriers that disappear when a certain biomass is reached. Different lifeforms behave and interact in different ways, and some caverns rely on later ones before they can be fully completed.
Most lifeforms produce seeds or reproduce in ways that the player can provoke; the player is able to carry a number of seeds for each type and drop or throw them. Caverns may contain several types of nutrient-rich areas which will have different effects on seeds planted in them. Some caverns contain unique lifeforms or pre-existing ecosystems, and may require specific lifeforms or challenges to be met for the higher biomass ratings, but most can be solved in many different ways; it is thus difficult but not impossible to make a five-star biomass rating unachievable.
The player has a jetpack with unlimited fuel which allows travel throughout the cavern system, and does not suffer fall damage. However they (and other lifeforms) can be harmed by certain ecological events such as acid or lava and some of the more vicious lifeforms. Progress is saved automatically and death results in merely a reset to the cavern entrance.
While the main aim is to raise biomass in caverns (initially to pass through them and escape to the safe base) the player also has other optional quests, such as locating a mobile research robot that had been lost underground previously, or finding other jetpack 'programs' which alter its behavior (such as increasing thrust or hovering automatically). The player is also given a research journal which contains information on the lifeforms and their behavior - this is filled automatically if the player witnesses a related event, and can provide useful information or hints for solving puzzles through what is present or not present. Conversations with the other characters are entirely linear but provide backstory, hints and objectives for the player.
Minimum System Requirements
- Windows XP / Vista / 7 / 8
- 2 GHz processor or faster
- 512 MB RAM (1 GB recommended)
- 3D graphics card that supports OpenGL 3.0 or OpenGL 2.1 with framebuffer extensions
- 400 MB HDD
- OS X 10.6.8. or later
- Intel Core 2 Duo 2GHz+ processor
- 512 MB RAM
- OpenGL 3.0 or OpenGL 2.1 with framebuffer extensions
- Two-button mouse recommended