I originally got this game because it was quite inexpensive by the time that I got it, and I had heard that it was pretty good. I played it and played it...and played it, until I beat it. Unlike most games where I lose focus and don't touch them for months (then I pick them up and beat them, sometimes), I never took a day off until I had experienced pretty much everything this game has to offer, which is quite a bit. Probably my favorite game off all time.
The only problem is the graphics, but only by today's standards. I remember thinking they were good, so I cannot complain there.