I beat level 2, and went around exploring. I found levels 7, 4, and 8. Still searching for level 3. Finding secrets hasn't been too hard, as they're mostly where you remember them from the first or 2nd quest. But since I haven't seen level 3, maybe I'm not looking in the right place. I went in level 4, but it ate me up and spit me out, so I'm going to keep looking for the 3rd level.