The screens look good. Gotta try it!
EDIT: Got to the end. Here are my impressions:
First, I miss some background music throughout the whole level. About the evinronments, you really do have a nice selection of tilesets and the layer work is top-notch, but the caves look very lifeless (which results not only from the lack of music but also from having such a small ammount of objects). Also, I'd like a bit more direction in the level. It feels like I'm just dropped there and then I have no idea where to go. With so little ammount of obstacles (which is perfectly fine, by me) and so many ways to the end, you kind of miss the point of having the huge world, because one can easily skip through most of it. You could keep the same number of screens and cut a lot of passages, so that one actually has to see everything, also making the level last longer.
Another issue I have with many levels, namely this one are the cutscenes. I always get the first impression of a level by the cutscenes and when they are not good, I won't like the level as much, later. It's an easily avoidable turn down, though! Why don't you line up the text? And chose a font with more... personality, that one looks so generic... I also think I found a typo in one of the scenes. You have put so much work on the world and your level could have been much better if you payed attention to these little details. A suggestion for you in particular: You made a very ince info screen. Why don't you make the cutscenes in that style, too? It is surely going to make your level more unique! One last thing: The ending is too underwhelming. I'm not sure what I would add there, but I was really like... "What, is that it??"
You should really work on this, though! Your level has a lot of unrealized potential!