Rimworld is a colony sim driven by an intelligent AI storyteller. It was initially released as a Kickstarter crowdfunding project in 2013 and was officially released in 2018.

Lens of the elemental Tetrad

Mechanics & Story
The sole controllable characters are the colonists. A colonist come with a set of skills. The player can assign a colonist task priority as well as directly order the colonists to perform a certain task, which can be useful especially during an enemy ambush.
Apart from skills, a colonist has many other properties such as health, mood, characteristics, beliefs, and more. The properties models the various aspects of a colonist and reflects how he/she interact with his/her surroundings. The player need to monitor the statuses of colonists, try to fulfill their needs and allocate tasks to the colonists based on their skills.

With colonists, the player can interact with all the other objects/systems in Rimworld, e.g. combats, animals, factions, ideologies, etc. Apart from the huge information of from the systems, the player also needs to deal with the external events generated by the AI storyteller. The storyteller will analyze the player’s situation and send different events to the colony. , some are good and some are bad. Medicines as gift from a friendly neighbouring colony can be helpful, whereby an eclicpse can disable all the solar panels, leading to power shortage.

In Rimworld, there is neither traditional 5-stage story nor heros calling for freedom and justice. There are imperfect colonists who wish to survive, imperfect players who make decisions, and the storyteller, a blackbox who seems to control everything beyond the colony. The story in Rimworld is about everyday struggle against the hash environment and unpredicable future, and most of the story is written by the player himself.

Aesthetics

Since Rimworld is emphasising on AI-storytelling, its graphics are mainly abstract icons. They are simple and distinctive, which makes it easier for the player to identify the many icons on the scene.

Technology

Unity is the main engine to build Rimworld. However, Rimworld uses its own object handlers to deal with its thousands of objects. Based on a post in 2015, the only Unity component Rimworld uses is sound emitter.

Lens of Flow & Lens of Problem Solving

The game starts with three survivors from a crashed space liner landing on the rim of the known world. The tutorial at the start of the game will teach the player about the basic actions. The initial resources, e.g. food, medicine, will run out quickly. So there is an initial push for the player to build the colony until it is self-sustained.

The challenge of games in Rimworld is gradually growing. In the default storyteller mode, the size of raids is proportional to the wealth of the colony. The richer the colony gets, the more powerful the enemy will be. This mechanic punish the players who throw all their resources into building and trading, while never build any defenses. Here is another example: as the player develops technology and unlocks new facilities for production, he/she needs to plan wisely to reduce the travel time from one site to another. More problems will arise. e.g. There may be a lack of manpower since number of production sites increases; if the colony primarily relies on automatic turrets as means of defence, it will be vulnerable to raids when the electricity system fails.

The ultimate goal is to launch an spaceship and escape from the colony. There are several means to achieve that, with which the most common and easist one is to build the spaceship in the colony. Building the spaceship requires a lot of materials/components which requires some time to find/craft. Once the spaceship is built, the player could activate the spaceship, which can only be launched after 15 days. In this period, the raids will take place more frequently, which means less time for colonists to recover from wounds and less time to repair the walls and turrets. Thus, before activating the spaceship, the player needs to do a lot of preparation: build defence smartly, update the equipments and weapons of the colonists, and keep the wealth of the colony at a reasonable amount.

Lens of The World & Lens of Freedom

The story of Rimworld takes place in the rim of known world. This leads to great diversity of human conditions. The player could interact with factions with much higher/lower technologies. A single combat can includes bows, swords, rifles and miniguns.

The modeling of colonists makes the game feel authentic. For example, the needs of colonists would grow along with the increase of wealth. Also, a colonist will constantly obsearve his/her situation and decide what they feel at the moment. If their mood is low, he/her is prone to a mental break. A colonist within a mental break no longer accept player’s commands, and will look for a way to release their feelings.

The modeling of objects is also disclosed to the player. When some status of an object changes, the player can expect to find the object’s properties related to the status change and the external force that causes the change. For example, fire can spread on wooden wall blocks because the flammability of the wooden wall is high.

The colony is at a distance from any authorities in the universe, and the player is on his/her own. This setting leads to the fact that, the game does provide evil (and profitable) options like having slaves, harvasting organs, and producing addictive drugs. In an developed society, these are obviously inhumane or immoral actions. But in the context of Rimworld, survival is the toppest priority. Plus, the game does not judge between good and evil, and the player is free to choose his/her ways of developing the colony.

Conclusion

All in all, the complex yet interesting modeling of the world, the uncertainty of the next moment and the freedom of actions make Rimworld one of the most addictive game I have ever played.