The First was an entirely new world that the story didn't leave with very few exceptions. A new force of nature, a new threat, a new culture, and the most powerful and devout of the Ascians.
Lakeland already stirred the pot with having wildly different visuals and something familiar superimposed on this alien world.
Amh Araeng we get that imposing view of the huge wall of Light looking over us, and the bleak atmosphere fits well.
Il Mheg is something we've never seen before, and has a healthy amount of whimsy.
Kholusia felt like Disneyland almost, and is where a big climax was so automatically gets more points.
The tempest was just a set dressing for Amaurot.
The zones in EW...
Sharlayan and Labyrinthos were talked about for a long, long time in the story, so while the zones are pretty, they feel like they slip by fast.
Thavnair we spend way too little time in.
Garlemald is just bleak and depressing, though felt on-par with ShB.
Mare Lamentorum just felt unfinished to me.
Elpis pretty much matched the feeling I felt in the First, and I would die for an entire expansion in this setting.
Ultima Thule is only really meant to be that endgame 'final sprint for the end' area that a lot of video games have.