An extraordinary game, but not perfect.
I never really care about bugs and graphics in a game. Gothic has many bugs, but very good graphics as well. What really matters for me in a RPG are quests, storyline, gameplay, and freedom.
Gothic has lots of original quests. Although most of them require you to retrieve an artifact or another, the way these missions are described and how they fit seamlessly into the main storyline makes them some of the best quests I have ever seen in an RPG. As for storyline, it's excellent as well, and clichee free. The ending, especially, is beautiful. You probably know the basic plot by know, so I won't spoil therest for you.
The gameplay does not excell, like the other features, however. The fighting system is difficult to understand and use, and will probably force you to load the last save game many times to fight a certain enemy, at least at the beggining. A mage is screwed if a range warrior reaches him, and using the spell "Ice Block", that freezes your enemy, is compulsory. However, by the end, you'll be very powerful, and even able to freeze anyone that dares come near you and then finish them one by one.
The game's weakest point, though, is it's linearity, and almost complete lack of freedom. At the beggining, you will be able to choose between 3 different factions, and each will have it's own unique quests. To my disappointment, this small amount of freedom lasts only during the first chapter (which ends after you become level 5), and after that, the story becomes completly linear. All that will be different will be the armor you get. As for quests, although they are very good, there are hardly any outside the main quest. During my game, I only encountered 2, though there are probably more than that. So all you can do, besides going on with the main story, is walking around the land fighting monsters and getting some rewards from dungeons. Though you aren't likely to bewilling to do that, thanks to the very addictive main quest and its storyline. You can't even get better armor outside that quest, since you won't be able to get the armor off a dead NPC no matter how hard you try.
Al for levelling up, here's how it works: you start the game with no skills. As you kill monsters, you gain experience points, and those points will eventually cause you to level up. At each level up, you are awarded 10 learning points, which you may choose to turn into either attributes, or skills, at the various trainers you find in each faction's camp, or out in the wilderness. This system has it's merits, since it offers you more freedom, but is not too realistic, and I like TES's way to do it more (for those who don't know how that one works: use a skill and you'll become better with it)
So, if you're a Morrowind fan, you might be discouraged by Gothic's almost complete lack of freedom, and different levelling system, like I was the first time I played. But play it, a little "Quality over Quantity" game won't hurt you, especially when that quality is outstanding, like Gothic's.