Deep, complex, enjoyable and incredible in almost every way.
I played it for a few days, trying to decide how I felt about it. It was a slow start, because I didn't fully understand the point—I couldn't see the forest for the trees. As I started collecting and completing quests I realized that the richness that I was seeing was real, not just a lack of understanding about the nature of the game itself, and it just keeps getting deeper. The world is absolutely huge, and there are hundreds of locations to explore.
Now on to specifics. The graphics are pretty fantastic, ranging from looking down at the cobblestone beneath you to looking up at the sun and watching the colors in the surrounding countryside bleach out. On the graphics front, the characters are the real weak part, but only in some ways. It's impressive that the lip-sync is so rich, but the characters themselves are strangely stiff, and stretched in strange ways. I think it's a good example of our having crossed the boundary between obviously-artificial characters and creepy-looking characters that are realistic in some ways and not realistic in others. Also on the graphics front, the frame rate seems to lag a bit, but not nearly as much as some of the other PS3 titles available now. It's not nearly consistent or frequent enough to outweigh all of the pros.
The audio is fantastic, with nice, rich surround fields that are deeply layered with sounds that really come across as having differing distances and intensities. I even seem to hear different species of birds on different days when I pay attention. Sometimes it seems that every item that I'm carrying makes a different noise. The score is fantastic, but the one gripe there is actually a boon to gameplay—sometimes you react and prepare for a fight simply because the score switches to combat mode before you can even see your enemy. Seriously, that's it.
After a few weeks of playing almost every day, I'm still intensely interested in the tangled web of plot arcs, obscure references and multi-part quests. As an interactive developer, I can't help thinking about how many people were involved in crafting such a huge adventure, how much organization was involved in managing it, and how much talent was involved in each aspect of its growth.
I'm not one for replaying games. I love the experience of picking something up, learning it and understanding it, and moving on. Oblivion has put a pause to that, and I can see going back to it again and again, even after I've had my fill with the first "completion", which at this rate will take me literally hundreds of hours. If you're interested in "open-ended" gameplay, in a fantasy/RPG context, you simply have no better option. This is by far the best value for a game that I've ever encountered, even at the next-gen price of $60, and I cannot recommend it enough.