The basic premise is similar to The Sims in that the player has to care for the needs of a several individuals - here each with a unique personality and different abilities. However the game is mission orientated and involves setting up a futuristic base and carrying out missions which involve mining minerals, developing relationships, harvesting resources to prevent running out of oxygen and power, collecting food, and fighting back alien attacks.
There are about 20 characters in this game.
- Venus Jones - The main character, a generally affable, red-headed woman. She is extremely versatile ability-wise, being able to run oxygen and power facilities, gather plants for nutrition, and the other basic jobs, and extremely effectively. She comes from the United States.
- Stig Svensson - Also versatile, but not as skilled. Due to his muscular build, eating is very important to him and increases his happiness more than other factors. He is said to come from Norway however the delvelopers have given him a thick Swedish accent.
- Tami La Belle - A Texan, with fairly good abilities. Loves chatting with liked base members, but can often become needy and prone to drinking.
- Dean Jefferson Brown - A basketball playing medical student from Los Angeles. He has an obsession with cleanliness, making personal hygiene very important to him.
- Candy Simpson - Californian airhead. Because her life revolves around shopping, she doesn't do much, as shown by her pitiful ability chart, which only features basic cleaning abilities.
- 'Nailer' McBride - A former death row inmate with a Scottish accent. Loves exercise, but has average ability area.
- Barbra Leechworth - A motivated sour person who is Blackwater's vice president; her paycheck is her important need. She and Venus are rivals and cannot stand each other.
An official bonus campaign was released in 2004. It has 5 missions and takes place on the planet Cobash.
A small 2D action-oriented game called Alien Horde was created to promote Space Colony. Players assume the role of Space Colony's leading lady Venus in this minigame. She has to fight back alien attacks and try to rescue Space Colony's hard-working Scandinavian biker Stig, plus she has to prevent running out of oxygen. Alien Horde is open-ended, and the gameplay becomes more intense with each level. Beside the same setting the gameplay of the minigame has not much in common with the more strategic-oriented gameplay of Space Colony.