Personally, I miss a person you follow noted from who was in the same situation as you, like Toorum. (Also miss Toorum mode)
I also miss some of the story aspects of the first one, with the dreams, and finding out the guy helping you is a the final boss, a giant cube (Which was amazingly well played with how the game is tile-based)
Also, I miss the different dungeon stones. There are a couple, but not as many as the original, mostly land based tiles now.
Although, this does mean that there's STILL reason to play the first one, it's not obsolete or anything