Coming late to the series, I was expecting this to be a phenomenal game, what with all the hype surrounding the series. Instead I had to force myself to finish this game. It is boring, with repetitive gameplay and a weak story that can't hold up to the slow pace of the game - by the end, I couldn't even remember what the point was. It can also be very frustrating as many of the fight mechanics don't work 100% the time (at least in the PC version), making winning the bigger fights largely a matter of luck.
On the plus side, the graphics are beautiful even for a game 6 years old, and the environments are richly detailed and alive. If the missions had more variety and the mechanics worked better it could have been great. Perhaps the story would have been more interesting if the narrative weren't constantly derailed by the games other flaws.
I'm not sure how this game spawned such a successful franchise, as it is a very weak offering. However I already own II & III, and plenty of people seem to like hem, so I will at least give them a shot. If they weren't already in my library I probably wouldn't buy them after playing this one though. I was very disappointed with it.