I started with 0.3.016 or maybe it was 017 already... Bronze doors were kinda new back then but already open. Since then, a lot has changed... Quests and skills were constantly added. New glyphs and spells too. New crafts... Too much to keep up with... And I might get the order wrong, but this is what I remember:
First really new expansion I witnessed was the opening of the Winch section. Lots of quests were added to help that. And chainmail armor became the next new thing.
New skins were added for Thunderclacker, Maulbernaut, Marfusang, Poison or Fire Carkarass, Wrathrats, Amigo consumers too I think... Guildhouses became a reality, with the massive scales in there. And Platemail armor was added. Some didn't show yet though. Crafting started to work around here, I think.
Then the Derghir village came into being, and ofcourse the Derghir themselves... And Dermorian females were added. Tlokes were seen for the first time.
Next, I guess, were new gobble types, then Gugrontid came and the caverns in Ojaroad and BDroad. Xiosia destroyed a guardtower and her tree grew in it's place. The Velnishi came to Yliakum, then the Riverling. Platinum became the new coveted commodity.
A second guildhouse type was then added. And the Gobble huts. And the Black Flame area... Also the Deathrealm changed a bit. Not really in layout, but mostly in art. Staircases started working so people could get on bridges and on guard towers. Cooking and Baking was introduced.
Soon after the rogue camp was added, which also helped with equipping some merchants with tents etc. And the Winch area was expanded with the new suspended platform and the buildings on either side.
Well, that's it "in a nutshell"... All along the way, quests, skills and trainers were constantly expanded upon. Something that added a lot to the gameplay, but doesn't have a visual impact.