An utterly massive, immersive and deep hardcore RPG, with good writing and level design. A playthrough will take forever and it's highly replayable. Alas, the pen-and-paper Pathfinder ruleset, while offering expansive and pliable character development, has many caveats. These include silly class concepts with a gross lack of balance between them, and a per-day ability system that poorly translates to combat-heavy video gaming. What's more, the game was plagued by a staggering number of (sometimes game-breaking) bugs and errors upon release, many of which are still not fixed countless patches later.
For all its flaws, it remains a magnificent game for those of us who like to meet adventuring challenges with number-crunching tactical creativity, and will probably be remembered as one of the finest RPGs of its decade along with the Pillars of Eternities.