Gargantua is an interstellar trade ship provided to you by the government to build on, produce and trade with. You will create intricate production chains, manage the population and workforce, build defences and travel to different planets to trade.
In Gargantua, every bullet you shot had to be produced or bought. You have to find most cost efficent ways to defend your ship while keeping your industries running. Different planets have different native resources, products and different needs, so you have to decide best route take to make money and supply your industries.
Everytime you gain a new contracter level, government will reward you. Choose wisely because choices will have permanent effect on your production chain, combat abilites and resource management capabilities. You can specilize or be a generalist, whatever fits your strategy best.