I've played the original Dungeon Siege (not the expansion yet)for a while, and it's not a bad game. It really does follow the Diablo II formula, though it doesn't have the same great atmosphere or high quality feel that D2 has.

Graphics are pretty good, and you can Zoom in and out, and rotate the camera for different points of view.

Fighting is done all by clicking on enemies, but your characters will just attack anything that's nearby whether you do or not. That's why some reviewers complained that you're just an observer more often than not.

Only have 2 playable characters so far, but I think the battles will become more interesting as that number increases.

The level up system in the game is interesting, as you simply get better at the kind of attacks you use the most. Cast lots of spells, and as the game goes on, you'll be very proficient with them... but not such a good fighter. Enemies disappear for good once defeated, so you can't just keep fighting them and have it both ways.