That's just it, initially Gothics feel like difficult hack'n'slashers and you wonder why you are even bothering, but soon it gets very rewarding. Exploration of the hand-crafted world, deadly combat, the constant equipment hunt that makes you leap in power nearly everytime(first time earning Shadow armor in G1 anyone?, Stonecrusher in G1 and Orc slayer in G2 anyone?) and the incessant tackle between factions that actually has an effect on the game instead of being flavoring over an otherwise mediocre product like Morrowind, all of these themes are shared over the Gothic series.
Though I agree with anyone who says that the story took a turn for the worse with the chosen one stuff in G2. The original is still the strongest storywise. Too bad that it's a fairly obscure German crpg, I'd like it if more people could share the unique experience.