Probably the most underrated game I've ever seen.
The point behind this game is to Explore, Build, and Fight. You start off with a very weak ship and about 100k credits depending on which difficulty you choose. The game's story is definitely It's weakest point. The story is horrible, the voice acting is much worse, and It's completely linear. You will probably end up skipping the story and getting right down to the empire building. As you start to collect more and more cash you will eventually have enough for a station. These range from stations that produce a certain good like Wheat or Beef. To weapons and equipment like Lasers, Shields, and Missiles. Each station requires products for it to produce it's primary product. For example, A Wheat Farm - which is one of the cheapest stations you can get early in the game. Requires a resource of Energy Cells. Now you can actually go to a station and buy Energy Cells then return them to the Wheat Farm. Or you could set up an automatic trade route which basically does the trading for you. Most stations require more then one resource. And you can simply set up trade routes for each of the resources that particular station needs. Once you own 3 or 4 stations and have a steady income in. You could connect stations into Complexes. Complexes link stations nearby. And the linked stations share resources. So instead of you sending a hauler to collect resources that a station needs. You could build the station that supplies that resource. For example, A Crystal Fab requires Energy, Silicon and Meatsteak Cahoonas to produce It's primary resource. Which is Crystals. A power plant uses crystals to produce Energy Cells. So you would connect the Crystal Fab and a Solar Power Plant together to form a complex. Now those building share resources. And you don't have to get haulers to constantly bring goods back and forth to the stations. You can link as many stations as you want. The universe is a dangerous place... There are Pirates that constantly try to destroy you're empire. And a mysterious race known as the Kha'ak always try to ruin your day. That's where combat comes in. Each ship is categorized in class. M1 being a Capital Ship. And M5 ships being Light Fighters. All of these types of ships defend you're empire. And also yourself. You can buy as many ships as you want and they could be used for defending a Station, Escorting a transport, or simply fighting. But eventually when you have the money. You can build an entire army of Fighters and Capital ships to defend you're empire or conquer the universe. It's really up to you.
Whichever way you decide to play X3: Reunion. There is much that awaits you in this vast universe. It requires alot of time and patience to get anywhere. But managing you're Fleet and building you're Empire is what makes this game very fun. I highly recommend this title to any Space sim fan. It may be overwhelming at first. But stay with it. And I promise you, you will not regret it.