Very addictive gameplay loop where you set your own goals and there's always something to be done in the factory. The game is a combination of a tower defence (against the aliens who dislike the pollution from your base) and factory simulator. Instead of having a set of ploppable machines that do complex stuff from absolutely basic ingredients, you have to create simpler machines and connect them in production lines. This way you can create stuff with increasingly complex properties - first you melt ore, then you use the metal plates to build basic circuitry, then robots, then space shuttles. And there's never an ultimate winning condition - you expand your colony as much as you want, almost indefinitely.

Also, there's lots of mods and game generation options modifying the game to your liking.

Very addictive gameplay loop where you set your own goals and there's always something to be done in the factory. The game is a combination of a tower defence (against the aliens who dislike the pollution from your base) and factory simulator. Instead of having a set of ploppable machines that do complex stuff from absolutely basic ingredients, you have to create simpler machines and connect them in production lines. This way you can create stuff with increasingly complex properties - first you melt ore, then you use the metal plates to build basic circuitry, then robots, then space shuttles. And there's never an ultimate winning condition - you expand your colony as much as you want, almost indefinitely. Also, there's lots of mods and game generation options modifying the game to your liking.