Dungeon Siege 1 is the first RPG ever to have no loading screens and weather effects like, rain, snow, etc.
Also area transistions from a forest to a cave changed as did the music, Dungeon Siege set the bar high, Dungeon Siege 2 offered even more in the way character classes, pets and so on.
Dungeon Siege 3 offers even more, A well done game engine also no loading screens and area transisions are smooth, as with the other Dungeon Siege games it's Linear with a few side quests.
I really like the artwork, level design and characters, I'm not even sure why some say it's short I have yet to finish and I'm level 10 now, The battles are alot harder then the demo also thats good.