It's more like Dungeon Siege in terms of how it plays. Rather than random dungeons, it's a fairly linear plot (though it is possible to skip areas if you can fight or run your way through the wilderness)
There's basically 6 or so different hair styles for each character class per sex, maybe as many faces. You can pick from maybe that many hair and skin colors. And you can pick the size of the character from tiny to fairly big (basicaly 50% to 150% of the normal character)
You can also use dye on your armor and shields. This generally doesn't change the looks much, but it depends on the armor. For instance, I had plate mail for my warrior and I wanted to dye it red so it would be like that armor Mordred had in Excalibur. (the whole thing was shiny red). But it just dyed the shoulder pads a little.