The metacritic review score, in this case, I would personally say is innaccurate. This game is immense, with a small price tag for the hours you can get out of it.
If I had to describe the game to someone, I would call it a singleplayer EVE online. But not only that, its a game where at the beginning you can scratch out a living as a trader in a universe with a living economy, or you can take part in skirmishes to fight your way to the top. Thing that I love about this game is the fact that say a pilot bails from a target ship, or you purchase a new ship. You can actually issue orders via a command console to any of your ships, including your current ship. Now of course you can fly them all yourself as well and take part in dog fights, launch boarding parties at vessels, or even later in the game take part in capital vs. capital ship battles. You could start a trading empire and purchase software for trade ships under your command where they act autonomously, seeking deals across the galaxy in your name. My point here is, the ability to loadout ships and amass fleets essentially means that if you choose so, you can turn the game into an RTS. The game can be as hands on as you make it, basically.
Not to mention, you can purchase and construct space stations and factories yourself, impacting the economy. Prices rise and fall across sectors, a stock market exists impacted by station construction or destruction, and various races have different products. You have reputation with these factions as well, and there are randomly generated missions that appear constantly at stations during play. You can pick sides in a large scale conflict between two of the factions, or go after a specific race yourself in a bid to become a pirate lord.
As I mentioned above, the game has immense potential for fun here. Being a sandbox game however, I will say the storyline missions for this game are poor. Sometimes bugs occur, your auto pilot can run you into things, etc. However, the flaws i've seen are vastly outshined by the positives, IMO. The graphics arent extremely good, as can be expected from a title getting a few years older now. No performance problems to mention except for occasional slow down during large battles, particle effect apocalypses, and certain nebulous sectors. The game IS also running calculations for an immense number of things in the background though!
One other large thing to mention is there was quite a large modding community for this game. I personally run the X Rebalance Mod, and it has made my game much better, fixing and filling out features. Recommend it as well, though there are plenty of other mods out there worth checking out too. I will say modding here is not quite as easy as say, skyrim, using the workshop to place the new files automatically.
+ Combat is thoroughly enjoyable, dogfights with fighter class ships a favorite, ducking in and out of capital ship fire
+ Diversity in styles and types of ships, i enjoy diversifying my fleet
+ Nonviolent methods to amass wealth and power as well, using trade to satisfy requirements for sectors
+ Large number of mods out there
+ RTS style commands for your ships
~ Graphics are looking dated
~ Sandbox haters, steer cleer!
- Bugs are occasional, but often when it rains it pours: autopilot & asteroids dont mix!
- Collisions: Your ships can seem magnetized. you will become frustrated, trust me. Theres a mod for that though!
- Poor plot missions
- Randomly generated missions can become repetitive
- Difficult learning curve -- There are tutorials and guides!
Plenty of people steer towards a certain type of 'space sandbox' but I for one have found my favorite game in the genre. No telling how many hours I'll end up with.
DISCLAIMER: Haven't played X3:Terran Conflict, or any other X3 game, ONLY X3: Albion Prelude! I've heard X Rebirth was shoddy, don't buy that thinking "its the next game, must be better!"