It is a single character RPG. I forget what you call it, but you see the world and your character from above.The combat is somewhat real time and some what phased. You can pause during combat to make selections of what you are going to do. You can also set up hot keys for your spells and such. It takes some time to get used to, but it works well.
The game is extremely non linear, easy to end up in the wrong place. There is a quick save feature and you can set up what ever number of quick save games you will have( not the three you have in Wiz 8 ).
There are three Ways, Mage, Warrior, and Survivor. And of course you can be male or female. You start with different attribute amounts and different skills, but any Way can learn any skill. That means if you want your mage can wear plate mail and swing a mace, axe, sword or whatever. There are a number of secondary attributes that are derived from the 4 prime ones( Strength, Intellegence, Agility, and Constuition). How they are derived varies between the Ways.
There are 96 'skills'. Some of these are really spells and some are skills. Repair lets you repair your weapons and armour. Meteror Strike is a fire based spell.
All of the stats on weapons and armour are random so replayability can be very high. A lot of the weapons, armour, and misc. have some kind of enhancement like +3 Strength, and some have more than 1.
There is a huge number of quests. There are a few fed-ex type, but mostly they involve some type puzzle solving. And the world is very large, I am not sure but I would guess at this time 2-4 times the size of Wizardry 8.
Sorry about the short first post, but I forgot I had to do something and ran out of time.
I would suggest the following places for more info:
http:\\www.larian.com
Spydah's Web( also has Wiz 8, NWN, MW and other sections)
The Locus Inn at RPGdot