Mild spoilers.
Gothic really opens up when you realise you can smack the tar out of everybody you meet.
Most games won't let you do that. Even Gothic II won't let you do it easily. You're meant to trade with NPCs and do quests for them, not immediately whack them upside the head and take all their worldly belongings. But Gothic is set in a fantasy prison colony. The attitude is very much "every man for himself". Guards will barely raise an eyebrow, let alone a weapon, as you rampage around knocking people out left and right. (And hey, they're all criminals, so you don't have to feel too bad about it.) The best part is when you greet the character after they regain consciousness, and they suck up to you about how you beat them in a "fair fight" so let's forget about it. Well, I removed 90% of your health before you could even turn around, but sure, we'll say it was fair...
The parts of the game that lean into this really shine. You start off incredibly weak and penniless, but you're given ample opportunity later to return as a powerful warrior and punish anyone who screwed you over in the early game. Near the end you get armor which makes you almost immune to weaponry, and get the chance to run around all the previously restricted areas walloping people. It's great fun and a brilliant emotional/mechanical payoff. Taking a merchant's entire inventory - stacks of potions, scrolls worth thousands of gold that you coveted as a new player - never gets old.
It has to be said that the game is janky as hell. The most dangerous enemy in the game is a gentle slope, which you will get stuck sliding on 99% of the time and will have to cheat your way out of or reload. You're fully expected to cheese enemies and exploit glitches. There are bizarre design decisions like not including an actual exit out of an wizard's tower you must teleport to in order to finish the game, so you have to yeet yourself into a lake or onto a nearby bit of terrain if you want to continue exploring nearby. A lot of the plot revolves around weed and everyone's puffing on a giant blunt at all times. The final boss bugged out and most of the intended enemies didn't attack me. But all of this brokenness is kind of charming! The core of the game is good enough to support it, and I'm glad they spent their time on varied locations and items rather than smoothing out the weirdness.
In comparison to its contemporaries like Morrowind, and even its own sequel, Gothic was miles behind in terms of world size, complexity, graphics, polish, and writing. But boy was it ahead in terms of beating people the heck up.