Gothic is a masterpiece of game design. The game world is huge, nevertheless, it makes sense as a whole and you do not get feeling that some parts were added just to make it bigger (which I felt when playing Gothic II and III and other RPGs). Though the world is big, it is not empty and it definitely is not populated by randomly placed monsters. The barriers in the world are again very natural (like the creatures that are too strong for the player at the given moment) and the player always has somewhere to go and a clue what to do. Compared to other open-world RPG games (including Gothic's sequels), this game has the most consistent world I've seen.
The controls are not usual, but once you get used to it, it is very effective. The only weak point is the inventory, which really could be done in a better way. However, it is just one thing, and it can't ruin the whole experience. The combat controls "improve" both with the skill of the character and with the skills of the player (the players timing is better and I had a feeling it also was easier with higher melee skills).
With this price, there is no excuse for not playing Gothic, if you are a RPG fan and you haven't played it yet.